In a potentiometer, the sensitivity can be increased by: MCQ with Answer and Explanation

In a potentiometer, the sensitivity can be increased by:
A. Decreasing the length of the wire
B. Increasing the current in the primary circuit
C. Increasing the length of the wire
D. Using a thicker wire
Answer: Option C
Solution (By JKSSB Mock Tests)
Potentiometer sensitivity (ability to detect small EMF changes) increases with longer wire because potential gradient (V/cm) decreases, allowing finer measurement of balancing length. Sensitivity ∝ length of wire. Decreasing length (B) reduces sensitivity; increasing current (C) increases potential gradient, reducing sensitivity; thicker wire (D) reduces resistance but doesn't directly affect sensitivity if current adjusted. Memory tip: 'Longer potentiometer wire ⇒ smaller potential gradient ⇒ higher sensitivity'. This experimental physics concept is frequently tested in competitive exams. Always link sensitivity to potential gradient: smaller gradient allows detection of smaller voltage differences.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1
The power factor in an AC circuit is defined as:
A. Both (a) and (c)
B. Ratio of apparent power to true power
C. Cosine of phase angle between voltage and current
D. Ratio of resistance to impedance

Correct Answer: Option A


Explanation:
Power factor = cosφ, where φ is phase angle between voltage and current. Also, power factor = R/Z (resistance/impedance) for series circuits, and = true power (W) / apparent power (VA). Thus both (a) and (c) are correct definitions. Memory tip: 'Power factor = cosφ = R/Z = P/S; ideal = 1 (purely resistive)'. This definition question tests AC circuit knowledge, crucial for competitive exams. Always link power factor to energy efficiency: low power factor means more current for same power, increasing losses.

This question belongs to: Science Physics
Question #2
The phenomenon of increase in frequency when source of sound approaches observer is called
A. Echo
B. Reverberation
C. Resonance
D. Doppler effect

Correct Answer: Option D


Explanation:
Doppler effect: apparent frequency change due to relative motion. Approaching increases frequency.

This question belongs to: Science Physics
Question #3
Three resistors 2 Ω, 3 Ω, 6 Ω are connected in parallel. Equivalent resistance is
A. 1 Ω
B. 11 Ω
C. 0.5 Ω
D. 1.5 Ω

Correct Answer: Option A


Explanation:
1/R = 1/2+1/3+1/6 = 3/6+2/6+1/6 = 6/6=1 => R=1 Ω.

This question belongs to: Science Physics