MCQ
A parallel plate capacitor is charged. If the plates are pulled apart:
  • A
    The capacitance increases.
  • B
    The potential difference increases.
  • C
    The total charge increases.
  • D
    The charge and potential difference remain the same.

Answer

  1. The potential difference increases.

Explanation:

Capacitance of a parallel plate capacitor.

$\text{C}=ε0\text{AdC}=ε0\text{Ad}$

A parallel plate capacitor is charged (battery is disconnected) then the plates are pulled apart, the capacitance decreases while the charge remains the same.

$\because$ Potentialdifference = ChargeCapacitance∵Potentialdifference = ChargeCapacitance.

$\therefore$ potential difference increases.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A magnet makes 40 oscillations per minute at a place having magnetic field intensity of 0.1 × 10–5 T. At another place, it takes 2.5 sec to complete one vibration. The value of earth’s horizontal field at that place is

(a) 0.25 × 10–6 T

(b) 0.36 × 10–6 T

(c) 0.66 × 10–8 T

(d) 1.2 × 10–6 T

A positively charged particle projected towards east is deflected towards north by a magnetic field. The field may be:
The same radioactive nucleus may emit?

The core of a transformer is laminated so that

(a) Ratio of voltage in the primary and secondary may be increased

(b) Rusting of the core may be stopped

(c) Energy losses due to eddy currents may be reduced

(d) Change in flux is increased

The inverse square law of intensity $\Big(\text{i.e., the intensity}\propto\frac{1}{\text{r}^2}\Big)$ is valid for a:
A wire is placed parallel to the lines of force in a magnetic field and a current flows in the wire. Then:

The capacity of a condenser in which a dielectric of dielectric constant 5 has been used, is  C. If the dielectric is replaced by another with dielectric constant 20, the capacity will become

(a)  

(b) 4C

(c)   

(d) 2C

For television broadcasting, the frequency employed is normally

(a) 30-300 MHz

(b) 30-300 GHz

(c) 30-300 KHz

(d) 30-300 Hz

A rod of length 20 cm is rotating with angular speed of 100 rps in a magnetic field of strength 0.5 T about it’s one end. What is the potential difference between two ends of the rod

(a) 2.28 V

(b) 4.28 V

(c) 6.28 V  

(d) 2.5 V

We can reduce eddy currents in the core of transformer

(a) By increasing the number of turns in secondary coil

(b) By taking laminated core

(c) By making step-down transformer

(d) By using a weak ac at high potential