Solved papers for NEET Physics Alternating Current / प्रत्यावर्ती धारा NEET PYQ-Alternating Current

done NEET PYQ-Alternating Current Total Questions - 22

• question_answer1) A wire of resistance R is connected in series with an inductor of reactance \[\omega L\].  Then quality factor of RL circuit is:                                                                                                                                               [AIPMT 2000]
  A)
   \[\frac{R}{\omega L}\]  
  done clear
  B)
                    \[\frac{\omega L}{R}\]
  done clear
  C)
   \[\frac{R}{\sqrt{{{R}^{2}}+{{\omega }^{2}}{{L}^{2}}}}\]             
  done clear
  D)
   \[\frac{\omega L}{\sqrt{{{R}^{2}}+{{\omega }^{2}}{{L}^{2}}}}\]
  done clear
  View Answer play_arrow

• question_answer2) For a series LCR circuit, the power loss at resonance is:                              [AIPMT 2002]
  A)
   \[\frac{{{V}^{2}}}{\omega L-\frac{1}{\omega C}}\]
  done clear
  B)
                    \[{{I}^{2}}\,C\,\omega \]
  done clear
  C)
   \[{{I}^{2}}R\]            
  done clear
  D)
   \[\frac{{{V}^{2}}}{\omega C}\]
  done clear
  View Answer play_arrow

• question_answer3) The peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without filter is 10V. The DC component of the output voltage is:                                                                [AIPMT (S) 2004]
  A)
   \[10/\sqrt{2}\,V\]                      
  done clear
  B)
  \[10/\pi \,\,V\]
  done clear
  C)
   \[-10\,\,V\]       
  done clear
  D)
        \[20/\pi \,\,V\]
  done clear
  View Answer play_arrow

• question_answer4) In a circuit, L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by \[{{45}^{o}}\]. The value of C is:                                                                                           [AIPMT (S) 2005]
  A)
   \[\frac{1}{2\pi f\,(2\pi fL+R)}\]
  done clear
  B)
        \[\frac{1}{\pi f\,(2\pi fL+R)}\]
  done clear
  C)
   \[\frac{1}{2\pi f\,(2\pi fL-R)}\]
  done clear
  D)
        \[\frac{1}{\pi f\,(2\pi fL-R)}\]
  done clear
  View Answer play_arrow

• question_answer5) A coil of inductive reactance \[31\,\,\Omega \] has a resistance of \[8\,\,\Omega \]. It is placed in series with a condenser of capacitative reactance \[25\,\,\Omega \]. The combination is connected to an a.c. soruce of 110 V. The power factor of the circuit is:                                                                                                          [AIPMT (S) 2006]
  A)
   0.56              
  done clear
  B)
    0.64   
  done clear
  C)
   0.80    
  done clear
  D)
  0.33
  done clear
  View Answer play_arrow

• question_answer6) What is the value of inductance I for which the current is a maximum in a series LCR circuit with \[C=10\,\mu F\] and to \[\omega =1000\,{{s}^{-1}}\]?                                                                                       [AIPMT (S) 2007]
  A)
   100 mH
  done clear
  B)
                    1 mH
  done clear
  C)
   Cannot be calculated unless R is known
  done clear
  D)
        10 mH
  done clear
  View Answer play_arrow

• question_answer7) 

  In an AC circuit the emf (e) and the current (i) at any instant are given respectively by  [AIPMPT (S) 2008]

  \[e={{E}_{0}}\sin \omega t\]

  \[i={{I}_{0}}\sin (\omega t-\phi )\]

  The average power in the circuit over one cycle of AC is

  A)
   \[\frac{{{E}_{0}}{{I}_{0}}}{2}\]
  done clear
  B)
                    \[\frac{{{E}_{0}}{{I}_{0}}}{2}\sin \phi \]
  done clear
  C)
   \[\frac{{{E}_{0}}{{I}_{0}}}{2}\cos \phi \]       
  done clear
  D)
        \[{{E}_{0}}{{I}_{0}}\]
  done clear
  View Answer play_arrow

• question_answer8) 

  The rms value of potential difference V shown in the figure is                        [AIPMT (M) 2011]

  A)
   \[{{V}_{0}}\]              
  done clear
  B)
        \[\frac{{{V}_{0}}}{\sqrt{2}}\]
  done clear
  C)
   \[\frac{{{V}_{0}}}{2}\]                       
  done clear
  D)
        \[\frac{{{V}_{0}}}{\sqrt{3}}\]
  done clear
  View Answer play_arrow

• question_answer9) A coil has resistance \[30\,\,\Omega \] and inductive reactance \[20\,\,\Omega \] at 50 Hz frequency. If an AC source of 200 V, 100 Hz, is connected across the coil, the current in the coil will be                             [AIPMT (M) 2011]
  A)
   4.0 A  
  done clear
  B)
        8.0 A  
  done clear
  C)
   \[\frac{20}{\sqrt{12}}A\]          
  done clear
  D)
        2.0 A
  done clear
  View Answer play_arrow

• question_answer10) A planet moving along an elliptical orbit is closest to the sun at a distance \[{{r}_{1}}\] and farthest away at a distance of \[{{r}_{2}}\]. If \[{{v}_{1}}\] and \[{{r}_{2}}\] are the linear velocities at these points respectively, then the ratio \[\frac{{{v}_{1}}}{{{v}_{2}}}\] is                                                                               [AIPMT (S) 2011]
  A)
   \[{{r}_{2}}/{{r}_{1}}\]           
  done clear
  B)
        \[{{({{r}_{2}}/{{r}_{1}})}^{2}}\]
  done clear
  C)
   \[{{r}_{1}}/{{r}_{2}}\]           
  done clear
  D)
        \[{{({{r}_{1}}/{{r}_{2}})}^{2}}\]
  done clear
  View Answer play_arrow

• question_answer11) In an AC circuit an alternating voltage \[e=200\sqrt{2}\sin \,100\,t\] volt is connected to a capacitor of capacity \[1\,\mu F\]. The \[rms\] value of the current in the circuit is                                                                    [AIPMT (S) 2011]
  A)
   100 mA           
  done clear
  B)
        200 mA
  done clear
  C)
   20 mA
  done clear
  D)
        10 mA
  done clear
  View Answer play_arrow

• question_answer12) A missile is fired for maximum range with a initial velocity of 20 m/s. If \[g=10\text{ }m/{{s}^{2}},\] the range of the missile is                                                                                                                                     [AIPMT (S) 2011]
  A)
   50 m
  done clear
  B)
                    60 m
  done clear
  C)
   20 m   
  done clear
  D)
        40 m
  done clear
  View Answer play_arrow

• question_answer13) The instantaneous values of alternating current and voltages in a circuit are given as \[i=\frac{1}{\sqrt{2}}\sin (100\pi t)\] ampere \[e=\frac{1}{\sqrt{2}}\sin (100\pi t+\pi /3)\] volt                                       [AIPMT (M) 2012] The average power in Watts consumed in the circuit is
  A)
   \[\frac{1}{4}\]             
  done clear
  B)
        \[\frac{\sqrt{3}}{4}\]
  done clear
  C)
   \[\frac{1}{2}\]             
  done clear
  D)
        \[\frac{1}{8}\]
  done clear
  View Answer play_arrow

• question_answer14) In an electrical circuit R, L, C and an AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is \[\pi /3\]. If instead, C is removed from the circuit, the phase difference is again \[\pi /3\]. The power factor of the circuit is                                     [AIPMT (S) 2012]
  A)
   1/2                  
  done clear
  B)
        \[1/\sqrt{2}\]    
  done clear
  C)
   1                    
  done clear
  D)
        \[\sqrt{3}/2\]
  done clear
  View Answer play_arrow

• question_answer15) A coil of self-inductance L is connected in series with a bulb - B and an AC source.  Brightness of the bulb decreases when                                                                                                                                                [NEET 2013]
  A)
   frequency of the AC source is decreased
  done clear
  B)
   number of turns in the coil is reduced
  done clear
  C)
  a capacitance of reactance \[{{X}_{C}}={{X}_{L}}\] is included in the same circuit
  done clear
  D)
   an iron rod is inserted in the coil
  done clear
  View Answer play_arrow

• question_answer16) A resistance 'R' draws power 'P' when connected to an AC source. If an inductance such that the impedance of the circuit becomes 'Z' the power drawn will the                                                                                   [NEET  2015]
  A)
   \[P{{\left( \frac{R}{Z} \right)}^{2}}\]               
  done clear
  B)
   \[P\sqrt{\frac{R}{Z}}\]  
  done clear
  C)
   \[P\left( \frac{R}{Z} \right)\]       
  done clear
  D)
        P
  done clear
  View Answer play_arrow

• question_answer17) 

  A series R-C circuit is connected to an alternating voltage source. Consider two situations:         [NEET (Re) 2015]

  1. When capacitor is air filled.

  2. When capacitor is mica filled.

  Current through resistor is i and voltage across capacitor is V then

  A)
   \[{{V}_{a}}<{{V}_{b}}\]                   
  done clear
  B)
   \[{{V}_{a}}>{{V}_{b}}\]
  done clear
  C)
   \[{{i}_{a}}>{{i}_{b}}\]         
  done clear
  D)
        \[{{V}_{a}}={{V}_{b}}\]
  done clear
  View Answer play_arrow

• question_answer18) An inductor 20 mH, a capacitor \[50\,\mu F\] and a resistor \[40\,\,\Omega \] are connected in series across a source of emf \[V=10\text{ }\sin \text{ }340t\]. The power loss in A.C. circuit is :-                                    [NEET - 2016]
  A)
   0.51 W            
  done clear
  B)
        0.67 W
  done clear
  C)
   0.76 W            
  done clear
  D)
        0.89 W
  done clear
  View Answer play_arrow

• question_answer19) An inductor 20 mH, a capacitor \[100\text{ }\mu \text{F}\] and a resistor \[50\text{ }\Omega \]are connected in series across a source of emf, V = 10 sin 314 t. The power loss in the circuit is                                                         [NEET - 2018]
  A)
   2.74 W
  done clear
  B)
   0.43 W
  done clear
  C)
   0.79 W
  done clear
  D)
        1.13 W
  done clear
  View Answer play_arrow

• question_answer20) A small signal voltage \[V(t)\text{ }=\text{ }{{V}_{0}}\,\sin \omega t\] is applied across an ideal capacitor C
  A)
   Current \[I(t),\] lags voltage \[V\left( t \right)\] by \[{{90}^{o}}\].
  done clear
  B)
   Over a full cycle the capacitor C does not consume any energy from the voltage source.
  done clear
  C)
   Current \[I(t)\] is in phase with voltage \[V(t)\].
  done clear
  D)
   Current \[I(t)\] leads voltage \[V(t)\] by \[\text{18}{{\text{0}}^{o}}\].
  done clear
  View Answer play_arrow

• question_answer21) A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is \[\frac{\pi }{3}\]. If instead C is removed from the circuit, the phase difference is again \[\frac{\pi }{3}\]between current and voltage. The power factor of the circuit is:                        [NEET 2020]
  A)
   0.5                  
  done clear
  B)
   1.0
  done clear
  C)
   -1.0                 
  done clear
  D)
        zero
  done clear
  View Answer play_arrow

• question_answer22) A \[40\,\,\mu F\]capacitor is connected to a 200 V, 50 Hz ac supply. The rms value of the current in the circuit is, nearly:                                                                                                                                 [NEET 2020]
  A)
   2.05 A
  done clear
  B)
        2.5 A
  done clear
  C)
   25.1 A
  done clear
  D)
        1.7 A
  done clear
  View Answer play_arrow