# 7th Class Science Electric Current and Its Effects Question Bank

### done Electric Current and Its Effects

• A)

B)

C)

D) None of these

• A) only one cell

B) only two cells

C) two or more cells

D) All of the above

• A) Electric iron

B) Electric immersion heater

C) Electric geyser

D) A battery

• A) Experiences a force when it is in a magnetic field

B) Experience no force when it is in a magnetic field

C) Experiences the force only if the field is of electromagnetic nature

D) All of the above

• A) for a few hours

B) a few minutes

C) for ever

D) for the duration for which current flows through it

• A) liquid

B) vapor

C) hot

D) cold

B) Fleming

C) Oersted

D) None of these

• A) decrease the amount of current

B) increase the amount of current

C) increase the power consumed in the circuit

D) safeguard against excessive current.

• A) Steel

B) Plastic

C) Stainless steel

D) Soft iron

• A) it is malleable

B) it is inexpensive

C) it has a very high melting point

D) it is a good conductor

• A) chemical energy into electrical energy

B) electrical energy into mechanical energy

C) electrical energy into light

D) electrical energy into chemical energy

• A) left side of the battery

B) right side of the battery

C) any where in the circuit

D) near the positive terminal of the bulb

• A) A simple circuit with one bulb and one cell

B) A simple circuit with one bulb and two cells

C) A simple circuit with two bulbs and one cell

D) A simple circuit with two bulbs and two cells

• A) Voltmeter

B) Ammeter

C) Tester

D) Cell

• A) It makes it easier to draw the circuit diagrams

B) It is essential to draw the circuit diagrams

C) It helps to show the direction of flow of current in a circuit

D) All of the above

• A) Stainless steel

B) Hard pressed carbon

C) Porcelain

D) Copper tungsten alloy

• A) Leclanche cell

B) Dry cell

C) Daniel cell

D) Simple voltaic cell

• A) Voltmeter

B) Ammeter

C) Electroscope

D) None of these

• A) Magnetic field is produced

B) Heat is developed in the coil

C) Energy is lost in the form of heat

D) All the above

• A) Current electricity

B) Electric magnetism

C) Magneto electricity

D) Electromagnetism

• A) Cu

B) Constantan

D) Nichrome

• A) closed plug key

B) cell

C) variable resistance

D) open plug key

• A) Fuses only allow the circuit to work if the rating is exactly right.

B) The third fuse will melt because the rating is too high.

C) Using a fuse with too high rating cause?s electric shocks.

D) The circuit may work, but the fault is not corrected.

• A) the negative terminal of one cell is connected to the negative terminal of the other cell

B) the negative terminal of one cell is connected to the positive terminal of the other cell

C) the positive terminal of one cell is connected to the positive terminal of the other cell

D) None of these

• A) a bulb

B) a filament

C) an element

D) a coil

• A) Electric heater

B) Electromagnet

C) Element

D) Filament

• A) is a safety device which prevents damage to electric circuits and possible fire.

B) is made up of an insulating material to avoid electric shocks.

C) is a device which is used to measure the flow of electric current through a circuit.

D) All of the above

• A) the coil of wire used in various electrical appliances based on heating effect of current

B) the coil of wire used in various electrical appliances based on magnetic effect of current

C) both the above

D) None of these

• A) the bulb is showing the heating effect but it does not glow.

B) the circuit is broken

C) both the above

D) None of these

• A) ISI

B) HCCI

C) AGMARK

D) KSK

•  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)

B) A$\to$ (q), B$\to$ (p), C$\to$ (r), D$\to$ (s)

C) A$\to$ (p), B$\to$ (q), C$\to$ (s), D$\to$ (r)

D) A$\to$ (q), B$\to$ (p), C$\to$ (s), D$\to$ (r)

•  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)

B) A$\to$ (r), B$\to$ (s), C$\to$ (t), D$\to$ (p), E$\to$ (q)

C) A$\to$ (q), B$\to$ (r), C$\to$ (p), D$\to$ (s), E$\to$ (t)

D) A$\to$ (t), B$\to$ (p), C$\to$ (s), D$\to$ (q), E$\to$(r)

• A) a connecting wire

B) a switch in 'ON' position

C) a switch in 'off? position

D) None of these

• A) A

B) B

C) C

D) None of these

• A) Positive terminal

B) Negative terminal

C) Either positive or negative terminal

D) None of these

• A) Element

B) filament

C) Conducting wire

D) none of these

• A) the switch

B) the handle

C) the element

D) the connecting wire

• A) Material of element

B) Length of wire

C) Thickness of wire

D) all of these

• A) Both A and R is true and R is the correct explanation of A.

B) Both A and R is true but R is not the correct explanation of A.

C) A is true but R is false.

D) A is false but R is true.

• A) Both A and R is true and R is the correct explanation of A.

B) Both A and R is true but R is not the correct explanation of A.

C) A is true but R is false.

D) A is false but R is true.

• A) Statement (1) is correct while statement (2) is incorrect.

B) Statement (2) is correct while statement (1) is incorrect.

C) Both statements are correct

D) Both statements are incorrect.

• A) Statement (1) is correct while statement (2) is incorrect.

B) Statement (2) is correct while statement (1) is incorrect.

C) Both statements are correct

D) Both statements are incorrect.

• A) Bulb

B) wire

C) Key

D) cell

• A) Electrical$\to$light

B) Electrical$\to$heat$\to$light

C) Chemical$\to$electrical$\to$heat$\to$light

D) Chemical$\to$electrical$\to$light$\to$heat

• A) P

B) Q

C) R

D) S

• A) Brightness of A increases but that of B decreases

B) Brightness of A remains the same but that of B decreases

C) Brightness of both A and B decreases

D) Brightness of both A and B increases

• A) A

B) B

C) C

D) D

• A) A is closed. B and C are open

B) A and B are closed but C is open

C) A, B and C are closed

D) Both (b) and (c)

• A) D only

B) A and B only

C) C and D only

D) B, C and D only

• A) a conductor having a low melting point

B) a conductor having a high melting point

C) an insulator having a low melting point

D) an insulator having a high melting point

• A) component

B) circuit

C) element

D) spring

• A) the flow of electric current through the electromagnet in the bell stops.

B) the current-starts to flow through the electromagnet

C) there occurs a decrease in the voltage of the current flowing through the electromagnet

D) None of the above

• A) Material of the wire

B) Length of the wire

C) Thickness of the wire

D) All of these

• A) Same kind are used for different purposes

B) Different kind are used for different purposes

C) Both the above are correct

D) None of these

• A) It loses magnetism

B) It deflects the magnetic needle

C) No effect on the compass

D) The magnetic needle faces in East-west direction

• A) The appliances will not get full voltage

B) The appliances will not get proper current

C) This can damage the appliances

D) This can damage the dome sting wiring due to overheating

• A) Using fewer loops of wire per meter in the coil

B) Decreasing the current in the wire

C) Removing the iron core

D) All of the above

• A) it avoids leakage of electricity

B) in case of short circuit, current passes to the earth

C) it completes the electric current

D) it reduces fluctuation

• A) flows and stops in succession

B) flows continuously

C) first flows in one direction and after some time in other direction

D) flows in the beginning and then stops Forever

• A) Electricity could not flow through the circuit

B) Too much electricity passed through the bulb filament

C) The wires melted in the heat

D) All of the above

• A) The bulb is connected across the 220 Volts, 60 Joules of energy is consumed for every second.

B) The bulb is connected across 60 Joules, 220 Volts of energy is consumed

C) 60 Unit of current will flow in the bulb

D) 220 Unit of current will flow in the bulb

• A) is a device based on heating effect of current

B) is a device based on magnetic effect of current

C) is a switch which automatically turns off when current in it exceeds the safe limit

D) None of these

• A) Few minutes

B) Few seconds

C) One second

D) Few cycles of supply voltage

• A) Less current flows in the leading wire as compared to that in the filament

B) The leading wire has more resistance than the filament

C) The leading wire has less resistance than the filament.

D) Filament has coating of fluorescent material over it

• A) Specific resistance of wire

B) Diameter of wire

C) Length of wire

D) Current passing through the wire

• A) 32 minutes

B) 16 minutes

C) 4 minutes

D) 2 minutes

• A) live wire

B) neutral wire

C) earth wire

D) live and neutral wires

• A)

B)

C)

D)

• A) Copper

B) Cobalt

C) Steel

D) Nickel

• A) More length

C) Less length

• A) Strength of the magnetic field decreases

B) Strength of the magnetic field increases

C) Amount of heat generated due to resistance decreases

D) Strength of the magnetic field remains constant

• A) Artificial magnet

B) Synthetic magnet

D) None of these

• A) Electric bell

B) Electric fan

C) Magnetic sticker

D) Television

• A) The heat from the light affects the switch.

B) The person in the bathroom may be electrocuted if water enters the switch.

C) The switch is less likely to be damaged outside the bathroom.

D) The warm air in the bathroom causes the switch to overheat.

• A) A only

B) A and C only

C) B and D only

D) B, C and D only

• A) D only

B) B and D only

C) A, B and C only

D) A, B, C and D

•  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)

B) A$\to$ (p), B$\to$ (q), C$\to$ (s), D$\to$ (r)

C) A$\to$ (q), B$\to$ (p), C$\to$ (r), D$\to$ (s)

D) A$\to$ (q), B$\to$ (p), C$\to$ (s), D$\to$ (r)

•  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)

B) A$\to$ (p), B$\to$ (q), C$\to$ (r), D$\to$ (s)

C) A$\to$ (r), B$\to$ (q), C$\to$ (p), D$\to$ (s)

D) A$\to$(q), B$\to$(s), C$\to$(r), D$\to$(p)

•  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)

B) A$\to$ (q), B$\to$ (p), C$\to$ (s), D$\to$ (r)

C) A$\to$ (r), B$\to$ (s), C$\to$ (p), D$\to$ (q)

D) A$\to$ (s), B$\to$ (r), C$\to$ (q), D$\to$ (p)

• A) a crane

B) an electric bell

C) Both of these

D) None of these

• A) It will show deflection

B) It will not show deflection

C) Sometimes it will show deflection and sometimes it will not show any deflection

D) None of the above is correct.

• A) Both A and R are true and R is the correct explanation of A.

B) Both A and R are true but R is not the correct, explanation of A.

C) A is true but R is false.

D) A is false but R is true.

• A) Both A and R are true and R is the correct explanation of A.

B) Both A and R are true but R is not the correct, explanation of A.

C) A is true but R is false.

D) A is false but R is true.

• A) Statement (1) and (3) are incorrect while statement (2) is correct.

B) Statement (1) and (2) are incorrect while (3) is correct.

C) All the statements are correct.

D) All the statements are incorrect.

• A)

B)

C)

D)

• A) Solar$\to$electrical

B) Solar$\to$light$\to$heat

C) Solar$\to$electrical$\to$light

D) Solar$\to$electrical$\to$light$\to$heat

• A)

B)

C)

D)

• A)

B)

C)

D)

• A)

B)

C)

D)

• A) Closed Closed Open Open

B) Closed Open Open Closed

C) Open Open Closed Closed

D) Open Closed Closed Open

• A) R only

B) R and S only

C) P, Q and R only

D) P, Q and S only

•  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

B) B

C) C

D) D