Page 1 - Worksheet 2

WORK SHEET -2; PHYSICS CLASS 12

CHAPTER -4; TOPIC –Moving Charges and Magnetism

SUB TOPIC – Force experienced by moving charges and Applications

1. How does the magnetic moment of an electron in a circular orbit of radius r and moving
with a speed v change, when the frequency of revolution is doubled?
2. A current carrying loop is free to turn in a uniform magnetic field B. Under what
conditions, will the torque acting on it be
(i) minimum and
(ii) maximum?
3. An ammeter and a milliammeter are converted from the same galvanometer. Out of the
two, which current measuring instrument has higher resistance?
4. What is the advantage of using radial magnetic field in a moving coil galvanometer?
5. A narrow beam of protons and deuterons, each having the same momentum, enters a
region of uniform magnetic field directed perpendicular to their direction of momentum.
What would be the ratio of the radii of the circular paths described by them?
6. Using the concept of force between two infinitely long parallel current carrying
conductors, define one ampere of current.
7. In a certain region of space, electric field and magnetic field are perpendicular to
each other. An electron enters in the region perpendicular to the directions of
both and and moves undeflected. Find the velocity of the electron.

8. Force on a current carrying conductor in a magnetic field is _________ .
9. Force on a charge q moving in a magnetic field B with velocity v at angle 0 is equal to
_________ .
10. The magnetic field of a straight solenoid carrying current l and having n turns per unit
length is _________