Question

A particle of mass m and charge q is moving with a velocity v in a magnetic field B as shown in the figure. Show that it follows a helical path. Hence, obtain its frequency of revolution.

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 ?