The Question is from neet-physics current-electricity , and it was created by the author SUBHANI

Question

The sensitivity of a potentiometer can be increased by:

SUBHANI · Accepted Answer

## CORE INFORMATION
✓ **Answer**: C
## CONCEPT FRAMEWORK
 **Primary Concept**: Potentiometer sensitivity
 **Related Topics**: Electrical measurements, Wheatstone bridge
 **Prerequisites**: Understanding of potential difference, resistance, and current.
## SOLUTION PATHWAY
**Given Information**:
  The question asks how to increase the sensitivity of a potentiometer.
  Sensitivity refers to the smallest potential difference that can be accurately measured.
**Method & Steps**:
A potentiometer works by comparing the potential difference of an unknown source with a known potential difference along a wire of uniform resistance.  The sensitivity is determined by the potential gradient along the wire.  A smaller potential gradient means higher sensitivity, as a small change in potential difference will result in a larger change in length along the wire.
 1. Analyze the potential gradient.
  Reasoning: The potential gradient ($V/L$) is the potential difference ($V$) across the potentiometer wire divided by its length ($L$).  $V = IR$, where $I$ is the current and $R$ is the resistance of the wire. Therefore, the potential gradient is $IR/L$.
  Formula/Rule: Potential gradient $= \frac{V}{L} = \frac{IR}{L}$
 2. Determine factors affecting sensitivity.
  Working: To increase sensitivity, we need to decrease the potential gradient.  This can be achieved by increasing $L$ (length of the wire) or decreasing $I$ (current) or decreasing $R$ (resistance of the wire).
  Key Point: A smaller potential gradient means a larger change in length for a given change in potential difference, thus increasing the sensitivity.
 3. Identify the correct option.
  Result: Increasing the length of the potentiometer wire ($L$) will decrease the potential gradient, thereby increasing the sensitivity.
  Verification:  The formula $\frac{IR}{L}$ shows that increasing $L$ directly reduces the potential gradient.
 ## OPTION ANALYSIS
A :x: Decreasing the length of the potentiometer wire increases the potential gradient, reducing sensitivity.
B :x: Increasing the current increases the potential gradient, reducing sensitivity.
C ✓: Increasing the length of the potentiometer wire decreases the potential gradient, increasing sensitivity.
D :x: Decreasing the resistance of the potentiometer wire decreases the potential difference across the wire, making measurements less precise. While it might seem counterintuitive, it reduces sensitivity because the voltage changes become smaller and harder to measure precisely.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing sensitivity with resolution: Sensitivity relates to the smallest measurable change, while resolution refers to the smallest measurable value.
  2.Incorrectly relating current to sensitivity:  A higher current does not mean higher sensitivity, it actually reduces it.
 **Quick Tips**:
  1.Remember the potential gradient formula:  $V/L = IR/L$
  2.Sensitivity is inversely proportional to the potential gradient.

SUBHANI · Answer

Decreasing the length of the potentiometer wire

SUBHANI · Answer

Increasing the current in the main circuit

SUBHANI · Answer

The correct Option is "Increasing the length of the potentiometer wire"

SUBHANI · Answer

Decreasing the resistance of the potentiometer wire

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