List of top Physics Questions on Conductance

In a superconducting ring, a persistent current has been flowing without decay for years. This is possible because

A cone made of conducting material is given a charge $ Q $. $ \sigma_1, \sigma_2, \sigma_3 $ and $ \sigma_4 $ are charge densities at four points $ P, Q, R $ and $ S $. $ P $ is at the vertex of the cone and $ Q, R, S $ are at the periphery of the base. Choose the correct option.

Find percentage change in capacitance if potential difference across it has been changed from V to 2V.
If current in a conductor \(3t^2 + 4t^3\), charge = \(?\), flow \(t = 1\; to\; t = 2s\)
The electric resistance of a wire is \( R \). If the length of the wire is increased to double by stretching it, then the new resistance of the wire is
When a force \(F_1\) acts on a particle, frequency is 6 Hz and when a force \(F_2\) acts, frequency is 8 Hz. What is the frequency when both the forces act simultaneously in same direction?
At what temperature will the resistance of a copper wire become three times its value at 0°C? (Temperature coefficient of resistance for copper \( \alpha = 4 \times 10^{-3} /°C \))
The incorrect statement in respect of chromyl chloride test is
A wire of resistance $R$ is stretched to double its length. Its new resistance will be: