2nd Year Physics Chapter 6 Test20. Alternating Current

Q1. Multiple choice questions (Attempt all · 10 × 1 = 10)

1. Unit of capacitive reactance is:
   1. Ohm
   2. Farad
   3. Henry
   4. Tesla
2. The angle between current and voltage in a resistor is:
   1. 90°
   2. 180°
   3. 0°
   4. 45°
3. The unit of self-inductance is:
   1. Ohm
   2. Farad
   3. Henry
   4. Henry
4. Mutual inductance between two coils is 1 henry if a current changing at the rate of 1 A/s in one coil induces emf of:
   1. 0.5 V in other coil
   2. 1 V in other coil
   3. 2 V in other coil
   4. 10 V in other coil
5. An alternating voltage is given by 20sin⁡(157t). The frequency of alternating voltage is:
   1. 50 Hz
   2. 25 Hz
   3. 100 Hz
   4. 75 Hz
6. The emf induced in a coil due to change of current in a neighboring coil is called:
   1. Self-induction
   2. Mutual induction
   3. Electromagnetic induction
   4. Capacitive induction
7. A capacitor is perfectly insulator for
   1. direct current
   2. alternating current
   3. direct as well as alternating current
   4. neither for direct current nor for alternating current
8. In an inductor, current:
   1. Lags voltage by 90°
   2. Leads voltage by 90°
   3. In phase with voltage
   4. Opposite to voltage
9. Opposition offered by capacitor to AC is called:
   1. Resistance
   2. Inductive reactance
   3. Capacitive reactance
   4. Impedance
10. A full wave bridge rectifier consists of
    1. no diode
    2. one diode
    3. two diodes
    4. four diodes