10 Question-answer on Magnetism
(a) The same as
(b) One half
(c) Double
(d) One third
Ans: ( a)
2. The ratio of magnetic fields due to small bar magnet at a given distance in the end on position to board side on position is
(a) ¼
(b) ½
(c) 1
(d) 2.
Ans: (d)
3. Magnetic fields do not interact with
(a) Stationary electric charge
(b) Moving electric charge
(c) Stationary permanent magnets
(d) Moving permanent magnets.
Ans: (a)
4. Magnetic field produced by electrons in atoms and molecules is due to their
(a) Spin motion only
(b) Orbital motion only
(c) Spin and orbital motion both
(d) Neither Spin nor orbital motion bot
Ans: (c)
5. A sensitive magnetic instrument can be shielded very effectively from outside magnetic field by placing it inside a box of
(a) Wood
(b) Plastic
(c) Metal of high conductivity
(d) Soft iron of high permeability
Ans: (d)
6. Two short magnets placed along the same axis with their like poles facing each other repel each other with a force which varies inversely as
(a) Distance
(b) Square of distance
(c) Cube of distance
(d) Forth power of distance
Ans: (d)
7. A current carrying loop is placed in a uniform magnetic field. The torque acting on it does not depend upon
(a) Area of loop
(b) Shape of loop
(c) Value of current
(d) Magnetic field
Ans: ( b)
8. A bar magnet is cut into two equal halves by a plane parallel to the magnetic axis. Of the following physical quantities, the one which remains unchanged is:
(a) Pole strength
(b) Magnetic moment
(c) Intensity of magnetization
(d) Moment of inertia
Ans:( c)
9. A circular current loop is replaced by a magnetic dipole. Then the equivalent magnetic dipole has a constant
(a) Pole strength m of each pole
(b) Length 2 l of dipole
(c) Product of m and 2l
(d) All of the above
Ans: ( c)
10. Magnetic lines of force are
(a) Continuous
(b) Discontinuous
(c) Sometimes continuous and sometimes discontinuous
(d) Nothing can be said
Ans: (a)