A dielectric is introduced between the elements of the condenser kept at a constant potential difference, then the charge on condenser

Options

A. decreases
B. increases
C. unchanged
D. may increase or decrease

Answer

To solve the problem of how the charge on a capacitor changes when a dielectric is introduced while keeping the potential difference constant, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Basic Formula**:
The relationship between charge (Q), capacitance (C), and voltage (V) is given by the formula:
\[ Q = C \cdot V \]
Here, Q is the charge stored in the capacitor, C is the capacitance, and V is the potential difference across the capacitor.

2. **Identify the Effect of Dielectric**:
When a dielectric material is introduced between the plates of a capacitor, the capacitance increases. The new capacitance (C') with the dielectric can be expressed as:
\[ C' = K \cdot C \]
where K is the dielectric constant (K > 1).

3. **Constant Voltage Condition**:
Since the potential difference (V) across the capacitor is kept constant, we can express the new charge (Q') on the capacitor after the introduction of the dielectric:
\[ Q' = C' \cdot V \]

4. **Substituting the New Capacitance**:
Substitute the expression for C' into the equation for Q':
\[ Q' = (K \cdot C) \cdot V \]
This simplifies to:
\[ Q' = K \cdot (C \cdot V) = K \cdot Q \]

5. **Conclusion**:
Since K is greater than 1, we conclude that:
\[ Q' > Q \]
Therefore, the charge on the capacitor increases when a dielectric is introduced while keeping the potential difference constant.

### Final Answer:
The charge on the capacitor increases when a dielectric is introduced between the plates while maintaining a constant potential difference.