Exams › JEE Main › Physics

In a meter-bridge experiment to find an unknown resistance S, the balance (null) point D is found 30 cm from the left end. If the known resistance R = 5.6 kohm is in the left gap, what is the value of S?

1. 2400 Ω
2. 240 Ω
3. 24 Ω
4. 2.4 Ω

Correct answer: 2400 Ω

Solution

At balance the ratio of gap resistances equals the ratio of the corresponding wire lengths.

Related JEE Main Physics questions

• A physical quantity X is defined as ε0L(ΔV/Δt), where ε0 denotes the permittivity of free space, L is a length, ΔV is a potential difference, and Δt is a time interval. The dimensional formula of X matches that of which of the following?
• A set of n identical resistors is arranged once in a series combination and once in a parallel combination. What is the ratio of the larger equivalent resistance to the smaller equivalent resistance?
• A resistance coil is connected to a battery. In which arrangement will the maximum heat be produced?
• A bulb is rated at 220 V and 100 W. If the applied voltage falls by 2.5% from its rated value, by what percentage of the rated power will the power output decrease?
• An ammeter has a coil resistance of R. To extend its measuring range by a factor of n, the shunt resistance needed should be:
• How does the drift velocity Vd depend on the strength of the applied electric field?

⚔️ Practice JEE Main Physics free + battle 1v1 →