MCQ's on Capacitance

1. A capacitor consists of two
    (a) insulation separated by a dielectric
    (b) conductors separated by an insulator
    (c) ceramic plates and one mica disc
    (d) silver-coated insulators

2. The capacitance of a capacitor is not influenced by
    (a) plate thickness
    (b) plate area
    (c) plate separation
    (d) nature of the dielectric

3. A capacitor that stores a charge of 0.5 C at 10 volts has a                 capacitance of  ---------- farad.
    (a) 5          (b) 20        (c) 10           (d) 0.05

4. In a cable capacitor, voltage gradient is maximum at the surface       of the
    (a) sheath
    (b) conductor
    (c) insulator
    (d) earth

5. The capacitance of a cable capacitor depends on
    (a) core diameter
    (b) insulation thickness
    (c) ratio of cylinder radii
    (d) potential difference

6. The insulation resistance of a cable capacitor depends on
    (a) applied voltage
    (b) insulation thickness
    (c) core diameter
    (d) ratio of inner and outer radii

7. The time constant of an R-C circuit is defined as the time during     which capacitor charging current becomes --------- percent of its        ------ value.
    (a) 37, final
    (b) 63, final
    (c) 63, initial
    (d) 37, initial

8. The period during which current and voltage changes take place        in a circuit is called -------- condition.
    (a) varying
    (b) permanent
    (c) transient
    (d) steady

9. In an R-C circuit connected across a d.c. voltage source, which         of the following is zero at the beginning of the transient state ?
    (a) drop across R
    (b) charging current
    (c) capacitor voltage
    (d) none of the above

10. Which of the following quantity maintains the same polarity             during charging and discharging of a capacitor ?
     (a) capacitor voltage
     (b) capacitor current
     (c) resistive drop
     (d) none of the above

11 While a capacitor is still connected to a power source, the                spacing between its plates is halved. which of its following              quantity would remain constant ?
    (a) field strength
    (b) plate charge
    (c) potential difference
    (d) electric flux density

12 After being disconnected from the power source, the spacing            between the plates of a capacitor is halved. which of the                    following quantity would be halved ?
    (a) plate charge
    (b) field strength
    (c) electric flux density
    (d) potential difference