In a potentiometer, if we increase the value of R, in which direction does the balance J shift?

Options

A. Same as initial point
B. Towards B
C. Towards A
D. Shift to entrance end

Explanation

To solve the question regarding the shift of balance J in a potentiometer when the resistance R is increased, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Potentiometer Setup**: A potentiometer consists of a long wire with a uniform cross-section and resistance, connected to a battery. It is used to measure the potential difference (voltage) across components.

2. **Effect of Increasing Resistance (R)**: When we increase the resistance R in the circuit, it affects the current flowing through the potentiometer wire. According to Ohm's Law (V = IR), if resistance increases while the voltage remains constant, the current (I) will decrease.

3. **Current Decrease**: As the resistance R increases, the current (I) through the potentiometer wire decreases. This is a crucial point because the current directly influences the potential gradient along the wire.

4. **Potential Gradient**: The potential gradient (V/L) is defined as the potential difference (V) across the length (L) of the wire. When the current decreases, the potential difference across the wire also decreases, leading to a decrease in the potential gradient.

5. **Impact on Balance Length**: A decrease in the potential gradient means that for a given potential difference, the length of wire required to balance the circuit (the balance length) will increase. This is because a lower potential gradient means that more length is needed to achieve the same voltage drop.

6. **Direction of Shift**: Since the balance length increases, the point J, which indicates the balance point, will shift towards the end of the wire connected to the higher potential (point B). Therefore, J will shift towards B.

7. **Conclusion**: Thus, when the resistance R is increased, the balance J shifts towards B.

### Final Answer:
When the value of R is increased in a potentiometer, the balance J shifts towards B.