7th Class Science Electric Current and Its Effects Question Bank

done Electric Current and Its Effects Total Questions - 92

• question_answer1)
  Which of the following is a symbol of switch for ?off? position in an electric circuit?
  A)
  done clear
  B)
  done clear
  C)
  done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer2)
  A battery consists of
  A)
  only one cell                 done clear
  B)
  only two cells done clear
  C)
  two or more cells          done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer3)
  Select the one in which heating effect of current is not used.
  A)
  Electric iron done clear
  B)
  Electric immersion heater done clear
  C)
  Electric geyser done clear
  D)
  A battery done clear
  View Solution play_arrow

• question_answer4)
  When an electric current is flowing through a conductor it
  A)
  Experiences a force when it is in a magnetic field done clear
  B)
  Experience no force when it is in a magnetic field done clear
  C)
  Experiences the force only if the field is of electromagnetic nature done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer5)
  The magnetic field around a current-carrying coil lasts
  A)
  for a few hours done clear
  B)
  a few minutes done clear
  C)
  for ever done clear
  D)
  for the duration for which current flows through it done clear
  View Solution play_arrow

• question_answer6)
  When electric current flows through a conductor, the conductor becomes
  A)
  liquid                           done clear
  B)
  vapor done clear
  C)
  hot                   done clear
  D)
  cold done clear
  View Solution play_arrow

• question_answer7)
  By whom was magnetic effect of current discovered?
  A)
  Faraday           done clear
  B)
  Fleming done clear
  C)
  Oersted          done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer8)
  A fuse is fixed in a circuit in order to
  A)
  decrease the amount of current done clear
  B)
  increase the amount of current done clear
  C)
  increase the power consumed in the circuit done clear
  D)
  safeguard against excessive current. done clear
  View Solution play_arrow

• question_answer9)
  Select the one that you will prefer to make an electromagnet.
  A)
  Steel                             done clear
  B)
  Plastic done clear
  C)
  Stainless steel         done clear
  D)
  Soft iron done clear
  View Solution play_arrow

• question_answer10)
  Tungsten is used for the manufacture of an electric bulb because
  A)
  it is malleable   done clear
  B)
  it is inexpensive done clear
  C)
  it has a very high melting point done clear
  D)
  it is a good conductor done clear
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• question_answer11)
  In an electric motor, conversion takes place of
  A)
  chemical energy into electrical energy done clear
  B)
  electrical energy into mechanical energy done clear
  C)
  electrical energy into light done clear
  D)
  electrical energy into chemical energy done clear
  View Solution play_arrow

• question_answer12)
  Key or switch in circuit is placed:
  A)
  left side of the battery done clear
  B)
  right side of the battery done clear
  C)
  any where in the circuit done clear
  D)
  near the positive terminal of the bulb done clear
  View Solution play_arrow

• question_answer13)
  In which circuit will the bulb or bulbs glow the brightest?
  A)
  A simple circuit with one bulb and one cell done clear
  B)
  A simple circuit with one bulb and two cells done clear
  C)
  A simple circuit with two bulbs and one cell done clear
  D)
  A simple circuit with two bulbs and two cells done clear
  View Solution play_arrow

• question_answer14)
  Which of the following instruments is used to check whether electricity is flowing through a substance or not?
  A)
  Voltmeter                     done clear
  B)
  Ammeter done clear
  C)
  Tester            done clear
  D)
  Cell done clear
  View Solution play_arrow

• question_answer15)
  Why are symbols used for electric components?
  A)
  It makes it easier to draw the circuit diagrams done clear
  B)
  It is essential to draw the circuit diagrams done clear
  C)
  It helps to show the direction of flow of current in a circuit done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer16)
  The acting contacts for circuit breakers are made of
  A)
  Stainless steel done clear
  B)
  Hard pressed carbon done clear
  C)
  Porcelain done clear
  D)
  Copper tungsten alloy done clear
  View Solution play_arrow

• question_answer17)
  The primary cell which is used in daily life is
  A)
  Leclanche cell              done clear
  B)
  Dry cell done clear
  C)
  Daniel cell                    done clear
  D)
  Simple voltaic cell done clear
  View Solution play_arrow

• question_answer18)
  Electric current is measured by a device called
  A)
  Voltmeter                     done clear
  B)
  Ammeter done clear
  C)
  Electroscope                done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer19)
  When electricity is passed through a coil
  A)
  Magnetic field is produced done clear
  B)
  Heat is developed in the coil done clear
  C)
  Energy is lost in the form of heat done clear
  D)
  All the above done clear
  View Solution play_arrow

• question_answer20)
  Study of relationship between electricity and magnetism is called
  A)
  Current electricity        done clear
  B)
  Electric magnetism done clear
  C)
  Magneto electricity done clear
  D)
  Electromagnetism done clear
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• question_answer21)
  What is the material for electric fuse?
  A)
  Cu                               done clear
  B)
  Constantan done clear
  C)
  Tin-lead alloy     done clear
  D)
  Nichrome done clear
  View Solution play_arrow

• question_answer22)
  The figure below is the symbol of:
  A)
  closed plug key done clear
  B)
  cell done clear
  C)
  variable resistance       done clear
  D)
  open plug key done clear
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• question_answer23)
  A house-owner replaces a failed fuse for the lights of the house. When the lights are switched on, the second fuse also fails. The house-owner then uses a third fuse with a higher rating than the previous two. Why is this not a sensible thing to do?
  A)
  Fuses only allow the circuit to work if the rating is exactly right. done clear
  B)
  The third fuse will melt because the rating is too high. done clear
  C)
  Using a fuse with too high rating cause?s electric shocks. done clear
  D)
  The circuit may work, but the fault is not corrected. done clear
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• question_answer24)
  To make a battery of two cells
  A)
  the negative terminal of one cell is connected to the negative terminal of the other cell done clear
  B)
  the negative terminal of one cell is connected to the positive terminal of the other cell done clear
  C)
  the positive terminal of one cell is connected to the positive terminal of the other cell done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer25)
  It is present in an electric bulb and glows when electric current is switched on. It is
  A)
  a bulb                          done clear
  B)
  a filament done clear
  C)
  an element                   done clear
  D)
  a coil done clear
  View Solution play_arrow

• question_answer26)
  It is a current carrying coil of an insulated wire wrapped around a piece of iron. It is called
  A)
  Electric heater              done clear
  B)
  Electromagnet done clear
  C)
  Element            done clear
  D)
  Filament done clear
  View Solution play_arrow

• question_answer27)
  Fuse
  A)
  is a safety device which prevents damage to electric circuits and possible fire. done clear
  B)
  is made up of an insulating material to avoid electric shocks. done clear
  C)
  is a device which is used to measure the flow of electric current through a circuit. done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer28)
  Element refers to
  A)
  the coil of wire used in various electrical appliances based on heating effect of current done clear
  B)
  the coil of wire used in various electrical appliances based on magnetic effect of current done clear
  C)
  both the above done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer29)
  Why does a bulb not glow when its filament is broken?
  A)
  the bulb is showing the heating effect but it does not glow. done clear
  B)
  the circuit is broken done clear
  C)
  both the above done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer30)
  Which mark is necessary on electrical appliances?
  A)
  ISI done clear
  B)
  HCCI done clear
  C)
  AGMARK done clear
  D)
  KSK done clear
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• question_answer31)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column-I	Column-II
  (A) Electric cell	(p)
  (B) Electric bulb	(q)
  (C) Battery	(r)
  (D) Switch	(s)

  A)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s) done clear
  B)
  A\[\to \] (q), B\[\to \] (p), C\[\to \] (r), D\[\to \] (s) done clear
  C)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (s), D\[\to \] (r) done clear
  D)
  A\[\to \] (q), B\[\to \] (p), C\[\to \] (s), D\[\to \] (r) done clear
  View Solution play_arrow

• question_answer32)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) CFL	(p) A safety device to prevent electric appliances
  (B) ISI	(q) The wire used in heater to get heat
  (C) Switch	(r) Consume less energy than bulb
  (D) Fuse	(s) Appliance is safe to use
  (E) Element	(t) Turns the circuit ON or OFF

  A)
  A\[\to \] (s), B\[\to \] (t), C\[\to \] (r), D\[\to \] (q), E\[\to \] (p) done clear
  B)
  A\[\to \] (r), B\[\to \] (s), C\[\to \] (t), D\[\to \] (p), E\[\to \] (q) done clear
  C)
  A\[\to \] (q), B\[\to \] (r), C\[\to \] (p), D\[\to \] (s), E\[\to \] (t) done clear
  D)
  A\[\to \] (t), B\[\to \] (p), C\[\to \] (s), D\[\to \] (q), E\[\to \](r) done clear
  View Solution play_arrow

• question_answer33)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 Some common electrical components can be represented by symbols. It is much easier to draw a circuit diagram using symbols. A circuit diagram of an electrical circuit is shown in the figure below. Look at the diagram and answer the questions. In the diagram, B represents
  A)
  a connecting wire done clear
  B)
  a switch in 'ON' position done clear
  C)
  a switch in 'off? position done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer34)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 Some common electrical components can be represented by symbols. It is much easier to draw a circuit diagram using symbols. A circuit diagram of an electrical circuit is shown in the figure below. Look at the diagram and answer the questions. Which part of the circuit diagram represents a bulb?
  A)
  A                                  done clear
  B)
  B done clear
  C)
  C                                 done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer35)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 1 Some common electrical components can be represented by symbols. It is much easier to draw a circuit diagram using symbols. A circuit diagram of an electrical circuit is shown in the figure below. Look at the diagram and answer the questions. The longer horizontal line in A represents which terminal of the cell?
  A)
  Positive terminal done clear
  B)
  Negative terminal done clear
  C)
  Either positive or negative terminal done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer36)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 We use various appliances based on heating effect of current in our daily life. Some such appliances are electric room heater, electric heater, hot plates, electric iron, hair dryers etc. All these contain a coil of wire called element. The coil of wire in an electric bulb is known as
  A)
  Element            done clear
  B)
  filament done clear
  C)
  Conducting wire          done clear
  D)
  none of these done clear
  View Solution play_arrow

• question_answer37)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 We use various appliances based on heating effect of current in our daily life. Some such appliances are electric room heater, electric heater, hot plates, electric iron, hair dryers etc. All these contain a coil of wire called element. Which part of an electric iron becomes hot and gives out heat?
  A)
  the switch done clear
  B)
  the handle done clear
  C)
  the element done clear
  D)
  the connecting wire done clear
  View Solution play_arrow

• question_answer38)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage - 2 We use various appliances based on heating effect of current in our daily life. Some such appliances are electric room heater, electric heater, hot plates, electric iron, hair dryers etc. All these contain a coil of wire called element. The amount of heat produced depends upon which of the following?
  A)
  Material of element      done clear
  B)
  Length of wire done clear
  C)
  Thickness of wire         done clear
  D)
  all of these done clear
  View Solution play_arrow

• question_answer39)
  DIRECTIONS: The questions in this segment consist of two statements, one labeled as "Assertion A" and the other labeled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): Fuse is a safety device which prevents damages to electrical circuits and possible fires. Reason (R): The fuse wire blows off and breaks the circuit and prevents fire and damage.
  A)
  Both A and R is true and R is the correct explanation of A. done clear
  B)
  Both A and R is true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer40)
  DIRECTIONS: The questions in this segment consist of two statements, one labeled as "Assertion A" and the other labeled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Reason (A): Steel core is used in an electromagnet. Reason (R): Steel gets permanently magnetized when the current flows through the coil wound around.
  A)
  Both A and R is true and R is the correct explanation of A. done clear
  B)
  Both A and R is true but R is not the correct explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer41)
  DIRECTIONS: Read the following two statements carefully and choose the correct options. Statement 1: Battery is a combination of two cells only. Statement 2: The positive and negative terminals are generally marked on the cells.
  A)
  Statement (1) is correct while statement (2) is incorrect. done clear
  B)
  Statement (2) is correct while statement (1) is incorrect. done clear
  C)
  Both statements are correct done clear
  D)
  Both statements are incorrect. done clear
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• question_answer42)
  DIRECTIONS: Read the following two statements carefully and choose the correct options. Statement 1: The heating up of a thin conducting wire on passing an electric current through it is known as heating effect of current. Statement 2: Various electrical appliances that are based on heating effect of current contain a coil of wire called element.
  A)
  Statement (1) is correct while statement (2) is incorrect. done clear
  B)
  Statement (2) is correct while statement (1) is incorrect. done clear
  C)
  Both statements are correct done clear
  D)
  Both statements are incorrect. done clear
  View Solution play_arrow

• question_answer43)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: Ritu has set up a circuit as shown. What should she put in the position A to make the bulb glow more brightly?
  A)
  Bulb                             done clear
  B)
  wire done clear
  C)
  Key                              done clear
  D)
  cell done clear
  View Solution play_arrow

• question_answer44)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: What energy changes take place in the figure given here, where a bulb glows with the help of a cell?
  A)
  Electrical\[\to \]light done clear
  B)
  Electrical\[\to \]heat\[\to \]light done clear
  C)
  Chemical\[\to \]electrical\[\to \]heat\[\to \]light done clear
  D)
  Chemical\[\to \]electrical\[\to \]light\[\to \]heat done clear
  View Solution play_arrow

• question_answer45)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: Study the circuit shown here. Which switch if opened will cause the light bulb to stop glowing?
  A)
  P                      done clear
  B)
  Q done clear
  C)
  R                                  done clear
  D)
  S done clear
  View Solution play_arrow

• question_answer46)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: In the figure given below, A, B and C are identical bulbs. What changes occur in the brightness of bulbs A and B when the switch S is closed?
  A)
  Brightness of A increases but that of B decreases done clear
  B)
  Brightness of A remains the same but that of B decreases done clear
  C)
  Brightness of both A and B decreases done clear
  D)
  Brightness of both A and B increases done clear
  View Solution play_arrow

• question_answer47)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: Which one is not a source of electric current? A.         B. C. D.
  A)
  A                                  done clear
  B)
  B done clear
  C)
  C                                 done clear
  D)
  D done clear
  View Solution play_arrow

• question_answer48)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: In the circuit diagram shown below, the bulb lights up when
  A)
  A is closed. B and C are open done clear
  B)
  A and B are closed but C is open done clear
  C)
  A, B and C are closed done clear
  D)
  Both (b) and (c) done clear
  View Solution play_arrow

• question_answer49)
  DIRECTIONS: On the basis of, following diagram / picture answer the questions given below: The picture below shows a shop that caught fire because of a short circuit. Which of the following could have resulted in the fire? A. the shopkeeper used fuses and circuit breakers. B. the shopkeeper bought an energy-saving appliance. C. The shopkeeper did not replace his frayed and damaged wires. D. The shopkeeper plugged too many appliances into one socket.
  A)
  D only                          done clear
  B)
  A and B only done clear
  C)
  C and D only               done clear
  D)
  B, C and D only done clear
  View Solution play_arrow

• question_answer50)
  Select the one that is a necessary requirement for a wire to be used as a fuse wire
  A)
  a conductor having a low melting point done clear
  B)
  a conductor having a high melting point done clear
  C)
  an insulator having a low melting point done clear
  D)
  an insulator having a high melting point done clear
  View Solution play_arrow

• question_answer51)
  There is a coil of wire in an electrical iron. This coil of wire is known as
  A)
  component                   done clear
  B)
  circuit done clear
  C)
  element          done clear
  D)
  spring done clear
  View Solution play_arrow

• question_answer52)
  When we switch on an electric bell
  A)
  the flow of electric current through the electromagnet in the bell stops. done clear
  B)
  the current-starts to flow through the electromagnet done clear
  C)
  there occurs a decrease in the voltage of the current flowing through the electromagnet done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer53)
  The amount of heat produced in a conductor when electric current flows through it depends on which of the following?
  A)
  Material of the wire done clear
  B)
  Length of the wire done clear
  C)
  Thickness of the wire done clear
  D)
  All of these done clear
  View Solution play_arrow

• question_answer54)
  Fuses of
  A)
  Same kind are used for different purposes done clear
  B)
  Different kind are used for different purposes done clear
  C)
  Both the above are correct done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer55)
  If you bring a magnetic compass near a conducting wire through which current is flowing, what will you observe?
  A)
  It loses magnetism done clear
  B)
  It deflects the magnetic needle done clear
  C)
  No effect on the compass done clear
  D)
  The magnetic needle faces in East-west direction done clear
  View Solution play_arrow

• question_answer56)
  One should not connect a number of electric appliances to the same power socket because
  A)
  The appliances will not get full voltage done clear
  B)
  The appliances will not get proper current done clear
  C)
  This can damage the appliances done clear
  D)
  This can damage the dome sting wiring due to overheating done clear
  View Solution play_arrow

• question_answer57)
  Which of the following actions will decrease the strength of the magnetic field of an electromagnet?
  A)
  Using fewer loops of wire per meter in the coil done clear
  B)
  Decreasing the current in the wire done clear
  C)
  Removing the iron core done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer58)
  In electric fittings, the wires are earthed because:
  A)
  it avoids leakage of electricity done clear
  B)
  in case of short circuit, current passes to the earth done clear
  C)
  it completes the electric current done clear
  D)
  it reduces fluctuation done clear
  View Solution play_arrow

• question_answer59)
  When the switch of an electric bell is on, then electric current in it
  A)
  flows and stops in succession done clear
  B)
  flows continuously done clear
  C)
  first flows in one direction and after some time in other direction done clear
  D)
  flows in the beginning and then stops Forever done clear
  View Solution play_arrow

• question_answer60)
  Pooja makes a simple circuit with one bulb and five cells. The bulb lights for an instant and then goes out. Why?
  A)
  Electricity could not flow through the circuit done clear
  B)
  Too much electricity passed through the bulb filament done clear
  C)
  The wires melted in the heat done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer61)
  Marking on a bulb is 60 W, 220 V. What does it signify?
  A)
  The bulb is connected across the 220 Volts, 60 Joules of energy is consumed for every second. done clear
  B)
  The bulb is connected across 60 Joules, 220 Volts of energy is consumed done clear
  C)
  60 Unit of current will flow in the bulb done clear
  D)
  220 Unit of current will flow in the bulb done clear
  View Solution play_arrow

• question_answer62)
  MCB
  A)
  is a device based on heating effect of current done clear
  B)
  is a device based on magnetic effect of current done clear
  C)
  is a switch which automatically turns off when current in it exceeds the safe limit done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer63)
  The fault clearing time of a circuit breaker is usually
  A)
  Few minutes done clear
  B)
  Few seconds done clear
  C)
  One second done clear
  D)
  Few cycles of supply voltage done clear
  View Solution play_arrow

• question_answer64)
  When current is passed through an electric bulb, its filament glows, but the wire leading current to the bulb does not glow because-
  A)
  Less current flows in the leading wire as compared to that in the filament done clear
  B)
  The leading wire has more resistance than the filament done clear
  C)
  The leading wire has less resistance than the filament. done clear
  D)
  Filament has coating of fluorescent material over it done clear
  View Solution play_arrow

• question_answer65)
  Which has no importance for fuse wire?
  A)
  Specific resistance of wire done clear
  B)
  Diameter of wire done clear
  C)
  Length of wire done clear
  D)
  Current passing through the wire done clear
  View Solution play_arrow

• question_answer66)
  If it takes 8 minutes to boil a quantity of water electrically, how long will it take to boil the same quantity of water using the same heating coil but with the current doubled?
  A)
  32 minutes                   done clear
  B)
  16 minutes done clear
  C)
  4 minutes        done clear
  D)
  2 minutes done clear
  View Solution play_arrow

• question_answer67)
  When main switch of the house circuit is put off, it disconnects the
  A)
  live wire done clear
  B)
  neutral wire done clear
  C)
  earth wire done clear
  D)
  live and neutral wires done clear
  View Solution play_arrow

• question_answer68)
  The proper representation of series combination of cells obtaining maximum potential is
  A)
              done clear
  B)
  done clear
  C)
              done clear
  D)
  done clear
  View Solution play_arrow

• question_answer69)
  A small rod is wound round with certain coils and current is allowed to pass for some time. When the rod was taken out, it was found not to attract iron. The material of the rod may be
  A)
  Copper       done clear
  B)
  Cobalt done clear
  C)
  Steel                             done clear
  D)
  Nickel done clear
  View Solution play_arrow

• question_answer70)
  A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of
  A)
  More length                  done clear
  B)
  less radius done clear
  C)
  Less length                   done clear
  D)
  more radius done clear
  View Solution play_arrow

• question_answer71)
  When the strength of the current flowing through a coil is increased
  A)
  Strength of the magnetic field decreases done clear
  B)
  Strength of the magnetic field increases done clear
  C)
  Amount of heat generated due to resistance decreases done clear
  D)
  Strength of the magnetic field remains constant done clear
  View Solution play_arrow

• question_answer72)
  A substance that acquires the properties of a natural magnet is called.
  A)
  Artificial magnet          done clear
  B)
  Synthetic magnet done clear
  C)
  Manmade magnet        done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer73)
  Electromagnet is not used in
  A)
  Electric bell                  done clear
  B)
  Electric fan done clear
  C)
  Magnetic sticker           done clear
  D)
  Television done clear
  View Solution play_arrow

• question_answer74)
  The electric light switch for a bathroom is sometimes fitted on the wall outside the bathroom.
  A)
  The heat from the light affects the switch. done clear
  B)
  The person in the bathroom may be electrocuted if water enters the switch. done clear
  C)
  The switch is less likely to be damaged outside the bathroom. done clear
  D)
  The warm air in the bathroom causes the switch to overheat. done clear
  View Solution play_arrow

• question_answer75)
  A light bulb is connected in series with a battery, a switch and some wires. However, the light bulb does not light up. What is/are the possible reason(s)? A. The battery is weak. B. The switch is closed C. The bulb has blown D. The wires are made of copper
  A)
  A only                          done clear
  B)
  A and C only done clear
  C)
  B and D only   done clear
  D)
  B, C and D only done clear
  View Solution play_arrow

• question_answer76)
  Marie conducted an experiment to find out if the number of bulbs arranged in series would affect the brightness of the bulbs. Which of the following variables should be kept the same? A. type of bulbs                        B. Number of wires C. types of batteries     D. Number of bulbs
  A)
  D only                          done clear
  B)
  B and D only done clear
  C)
  A, B and C only           done clear
  D)
  A, B, C and D done clear
  View Solution play_arrow

• question_answer77)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) Battery	(p) The thin wire in an electrical bulb that glows when electrical current passes through it
  (B) Filament	(q) Combination of two or more cells
  (C) Electric geyser	(r) Makes use of heating effect of current
  (D) Electric bell	(s) Electromagnet

  A)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s) done clear
  B)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (s), D\[\to \] (r) done clear
  C)
  A\[\to \] (q), B\[\to \] (p), C\[\to \] (r), D\[\to \] (s) done clear
  D)
  A\[\to \] (q), B\[\to \] (p), C\[\to \] (s), D\[\to \] (r) done clear
  View Solution play_arrow

• question_answer78)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) MCB	(p) Filament
  (B) Electromagnet	(q) Element
  (C) Electric kettle	(r) Electric bell
  (D) Electric bulb	(s) Safety device

  A)
  A\[\to \] (s), B\[\to \] (r), C\[\to \] (q), D\[\to \] (p) done clear
  B)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s) done clear
  C)
  A\[\to \] (r), B\[\to \] (q), C\[\to \] (p), D\[\to \] (s) done clear
  D)
  A\[\to \](q), B\[\to \](s), C\[\to \](r), D\[\to \](p) done clear
  View Solution play_arrow

• question_answer79)
  DIRECTIONS: Match Column-I with Column-II and select the correct answer using the codes given below the columns.

  Column - I	Column - II
  (A) The fuse wire is generally an alloy of	(p) the metal of an electrical appliance is earthed
  (B) Electric fuse is connected in	(q)  the live wire and the neutral wire come in direct contact
  (C) To avoid the risk of electric shocks	(r) Lead and tin
  (D) A short \[\]circuit occurs whenever	(s) Series in the beginning of the electric circuit

  A)
  A\[\to \] (p), B\[\to \] (q), C\[\to \] (r), D\[\to \] (s) done clear
  B)
  A\[\to \] (q), B\[\to \] (p), C\[\to \] (s), D\[\to \] (r) done clear
  C)
  A\[\to \] (r), B\[\to \] (s), C\[\to \] (p), D\[\to \] (q) done clear
  D)
  A\[\to \] (s), B\[\to \] (r), C\[\to \] (q), D\[\to \] (p) done clear
  View Solution play_arrow

• question_answer80)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage When an electric current passes through a wire, it behaves like a magnet. This is the magnetic effect of current. When the electric current is switched off, the coil generally loses magnetism. Such coils are called electromagnets. Which of the following make use of electromagnets?
  A)
  a crane            done clear
  B)
  an electric bell done clear
  C)
  Both of these                done clear
  D)
  None of these done clear
  View Solution play_arrow

• question_answer81)
  DIRECTIONS: Read the passage given below and answer the questions that follow. Passage When an electric current passes through a wire, it behaves like a magnet. This is the magnetic effect of current. When the electric current is switched off, the coil generally loses magnetism. Such coils are called electromagnets. Look at the following diagram and tell if compass needle placed near the connecting wire will show deflection when the switch in the circuit is in 'ON' position?
  A)
  It will show deflection done clear
  B)
  It will not show deflection done clear
  C)
  Sometimes it will show deflection and sometimes it will not show any deflection done clear
  D)
  None of the above is correct. done clear
  View Solution play_arrow

• question_answer82)
  DIRECTIONS: The questions in this segment consist of two statements, one labeled as "Assertion A" and the other labeled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): It is fatal to touch a live wire with bare feet and uncovered hands. Reason (R): The electric current passes through the body to the earth forming a circuit and bums the blood.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct, explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer83)
  DIRECTIONS: The questions in this segment consist of two statements, one labeled as "Assertion A" and the other labeled as "Reason R". You are to examine these two statements carefully and decide if the Assertion A and Reason R are individually true and if so, whether the reason is a correct explanation of the assertion. Select your answers to these items using codes given below. Assertion (A): When a battery is short-circuited, the terminal voltage is zero. Reason (R): In the situation of a short-circuit, the current is zero.
  A)
  Both A and R are true and R is the correct explanation of A. done clear
  B)
  Both A and R are true but R is not the correct, explanation of A. done clear
  C)
  A is true but R is false. done clear
  D)
  A is false but R is true. done clear
  View Solution play_arrow

• question_answer84)
  DIRECTIONS: Read the following three statements carefully and choose the correct option. Statement 1: The emf of a battery equal the potential difference between its terminals when the terminals are not connected externally. Statement 2: Terminals potential difference can be greater than emf of cell. Statement 3: When current is flowing in circuit then terminal voltage is less than emf of cell.
  A)
  Statement (1) and (3) are incorrect while statement (2) is correct. done clear
  B)
  Statement (1) and (2) are incorrect while (3) is correct. done clear
  C)
  All the statements are correct. done clear
  D)
  All the statements are incorrect. done clear
  View Solution play_arrow

• question_answer85)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: Which of the following objects will make the bulb glow when put in position A of the material tester shown here.
  A)
                      done clear
  B)
  done clear
  C)
     done clear
  D)
  done clear
  View Solution play_arrow

• question_answer86)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: Which of the following energy conversions takes place in the figure given here?
  A)
  Solar\[\to \]electrical done clear
  B)
  Solar\[\to \]light\[\to \]heat done clear
  C)
  Solar\[\to \]electrical\[\to \]light done clear
  D)
  Solar\[\to \]electrical\[\to \]light\[\to \]heat done clear
  View Solution play_arrow

• question_answer87)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: Bulb in which of the following arrangements will be able to glow?
  A)
                        done clear
  B)
  done clear
  C)
                      done clear
  D)
  done clear
  View Solution play_arrow

• question_answer88)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: In which circuit the bulb will not light up?
  A)
            done clear
  B)
  done clear
  C)
            done clear
  D)
  done clear
  View Solution play_arrow

• question_answer89)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: Shayna used similar bulbs, batteries and wires to set up four circuits as shown below. Which of the circuits will have the brightest bulbs?
  A)
             done clear
  B)
  done clear
  C)
             done clear
  D)
  done clear
  View Solution play_arrow

• question_answer90)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: In the circuit below, which switch should be left open and which switch should be left closed so that only bulb Y lights up? Switch A          Switch B          Switch C          Switch D
  A)
  Closed             Closed             Open               Open   done clear
  B)
  Closed             Open               Open               Closed done clear
  C)
  Open               Open               Closed             Closed done clear
  D)
  Open               Closed             Closed             Open done clear
  View Solution play_arrow

• question_answer91)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: Four different circuits are shown below. In which of the above circuits would the bulb light up?
  A)
  R only                          done clear
  B)
  R and S only done clear
  C)
  P, Q and R only           done clear
  D)
  P, Q and S only done clear
  View Solution play_arrow

• question_answer92)
  DIRECTIONS: On the basis of following diagram / picture answer the questions given below: The diagram shows an electric bell which materials would be suitable for the parts labeled P, Q and R?

  	P	Q	R
  A	soft iron	brass	soft iron
  B	soft iron	soft iron	spring steel
  C	soft iron	brass	brass
  D	spring steel	soft iron	spring steel

  A)
  A                                  done clear
  B)
  B done clear
  C)
  C                                 done clear
  D)
  D done clear
  View Solution play_arrow