Wheatstone Bridge

Mediumphysics

In a balanced Wheatstone bridge, if P = 10 Ω, Q = 20 Ω, and R = 15 Ω, what is S?

Select the correct option:

30 Ω

7.5 Ω

45 Ω

5 Ω

🔒 Solution Hidden from View

Submit your answer to unlock the detailed step-by-step solution.

About This Question

Subject: physics
Chapter: current electricity
Topic: wheatstone bridge
Difficulty: Medium
Year: 2025

Solution

Correct Answer:

30 Ω

Balance Condition: A Wheatstone bridge is 'balanced' when the potential difference across the galvanometer is zero, meaning no current flows through it.
- Ratio Rule: $\frac{P}{Q} = \frac{R}{S}$ .
Rearrange for $S$ :
- $S = R \times \frac{Q}{P}$ .
Substitution:
- $S = 15 \times \frac{20}{10}$
- $S = 15 \times 2 = 30 Ω$ .
Result: The value of the unknown resistor $S$ is 30 Ω.

This medium difficulty physics question is from the chapter current electricity, covering the topic of wheatstone bridge. It appeared in the 2025 exam.

Looking for more practice? Explore all physics questions or browse current electricity questions on RankGuru.

Wheatstone Bridge

Select the correct option:

Solution

🔒 Solution Hidden from View

More wheatstone bridge Practice Questions

In a balanced Wheatstone bridge the galvanometer shows no deflection, so which relation among the fo...

Three arms of a Wheatstone bridge contain resistances of 4 (\Omega), 8 (\Omega), and 6 (\Omega...

Balance condition for Wheatstone bridge (arms P, Q, R, S)?

Balanced Wheatstone bridge condition:

The resistance of each arm of the Wheatstone bridge is 10 Ohm. A resistance of 10 Ohm is connected i...

About This Question

Solution