CBSE  /  Class 12  /  Physics  /  Alternating Current

  • 1. 
    The band width of a series resonant circuit is :

  • f0/Q0
  • \(\frac{R}{2πL}\)
  • \(\frac{R}{4πL}\)
  • 4R

  • 2. 
    A rejector circuit is:

  • series resonant circuit
  • parallel resonant circuit
  • LCR circuit
  • None of these

  • 3. 
    The inductive reactance of an inductor coil of \(\frac{1}{π}\) H at 50 Hz is:

  • \(\frac{50}{π}\) Ω
  • \(\frac{π}{50}\) Ω
  • 100 Ω
  • 50 Ω

  • 4. 
    In pure inductive circuit current

  • lags behind emf by π/2
  • leads the emf by π/2
  • lags behind emf by π
  • leads the emf by π

  • 5. 
    The current through an inductor of 1H is given by I = 3t sin t. The voltage across the inductor of 1 H is:

  • 3 sin t + 3 cos t
  • 3 sin t + 3t cos t
  • 3 cos t + t sin t
  • 3t cos t + sin t

  • 6. 
    Two coils X and Y are connected in series across a 240 V, 50 Hz supply. The resistance of X is 5Ω and inductance of Y is 0.02 H. The power consumed is 3 kW and the power factor is 0.75. The impedance of the circuit is:

  • 0.144 Ω
  • 1.44 Ω
  • 14.4 Ω
  • 144 Ω

  • 7. 
    In the above problem, the value of the resistance of the coil Y is:

  • 0.58 Ω
  • 5.8 Ω
  • 1.16 Ω
  • 11.6 Ω

  • 8. 
    An electric circuit containing capacitor only suffers:

  • equal resistance for A.C. and D.C.
  • Resistance of A.C. > Resistance of D.C.
  • Resistance for A.C. < Resistance of D.C.
  • offers infinite resistance for D.C.

  • 9. 
    The average power dissipation in pure inductance or capacitance is:

  • \(\frac{1}{2}\) LI²
  • \(\frac{3}{2}\) CV²
  • either (a) or (b)
  • zero

  • 10. 
    In the series L-C-R circuit, the voltmeter and ammeter readings are:
    MCQ Questions for Class 12 Physics Chapter 7 Alternating Current with Answers

  • V = 100 Volts, I = 2A
  • V = 100 Volts, I = 5A
  • V = 1000 Volts, I = 2A
  • V = 300 Volts, I = 1A
Report Question
warning
Practice More On Alternating Current
Quiz 1 Quiz 2 Quiz 3
access_time
  Time