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 ?
Dipoles, whether electric or magnetic, are characterised by their dipole moments, which are vector quantities. Two equal and opposite charges separated by a small distance constitute an electric dipole, while a current carrying loop behaves as a magnetic dipole. Electric dipoles create electric fields around them. Electric dipoles experience a torque when placed in an external electric field.
An electron is revolving around the nucleus in a circular orbit with a speed of 10⁷ m s⁻¹. If the radius of the orbit is 10⁻¹⁰ m, find the current constituted by the revolving electron in the orbit.
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