Question

In a hydrogen atom, the electron moves in an orbit of radius 2 Å making 8 × 10¹⁴ revolutions per second. Find the magnetic moment associated with the orbital motion of the electron.

What is current sensitivity of a galvanometer ? Show how the current sensitivity of a galvanometer may be increased. "Increasing the current sensitivity of a galvanometer may not necessarily increase its voltage sensitivity." Explain.

A moving coil galvanometer has a resistance 15 Ω and takes 20 mA to produce full scale deflection. How can this galvanometer be converted into a voltmeter of range 0 to 100 V ?

Assertion (A) : A proton and an electron enter a uniform magnetic field B⃗ with the same momentum p⃗ such that p⃗ is perpendicular to B⃗. They describe circular paths of the same radius. Reason (R) : In a magnetic field, orbital radius r is equal to p/qB.

Assertion (A) : The energy of a charged particle moving in a magnetic field does not change. Reason (R) : It is because the work done by the magnetic force on the charge moving in a magnetic field is zero.