Question

If the plates of a parallel plate capacitor connected to a battery are moved close to each other, then
A. the charge stored in it, increases.
B. the energy stored in it, decreases.
C. its capacitance increases.
D. the ratio of charge to its potential remains the same.
E. the product of charge and voltage increases.
Choose the most appropriate answer from the options given below :

• A. A, B and E only
• B. A, C and E only
• C. B, D and E only
• D. A, B and C only

Answer 1

The Correct Option is B

If the plates of a parallel plate capacitor connected to a battery are moved close to each other, then:

A. the charge stored in it, increases.

B. the energy stored in it, decreases.

C. its capacitance increases.

D. the ratio of charge to its potential remains the same.

E. the product of charge and voltage increases.

Choose the most appropriate answer from the options given below:

Explanation:

Let's analyze each statement:

A. the charge stored in it, increases.

The capacitance of a parallel plate capacitor is given by: $$C = \frac{\epsilon_0 A}{d}$$ where \(A\) is the area of the plates and \(d\) is the distance between them. When the plates are moved closer, \(d\) decreases, so the capacitance \(C\) increases. Since \(Q = CV\), and the voltage \(V\) is kept constant by the battery, the charge \(Q\) increases. Thus, A is correct.

B. the energy stored in it, decreases.

The energy stored in a capacitor is given by: $$U = \frac{1}{2}CV^2$$ Since \(C\) increases and \(V\) is constant, the energy \(U\) increases, not decreases. Thus, B is incorrect.

C. its capacitance increases.

As explained in A, when the plates are moved closer, the capacitance \(C\) increases. Thus, C is correct.

D. the ratio of charge to its potential remains the same.

The ratio of charge to potential is \(Q/V = C\). Since \(C\) increases, the ratio also increases, not remains the same. Thus, D is incorrect.

E. the product of charge and voltage increases.

Since \(Q = CV\) and \(C\) increases, and \(V\) is constant, the charge \(Q\) increases. Therefore, the product \(QV\) increases. Thus, E is correct.

Conclusion:

The correct statements are A, C, and E.