CBSE Class 12 Physics Moving Charges and Magnetism Quiz 2

1. What happens to the magnetic field at the centre of a circular current carrying coil if we double the radius of the coil keeping the current unchanged?

A halved B doubled C quadrupled D remains unchanged

2. When we double the radius of a coil keeping the current through it unchanged, what happens to the magnetic field directed along its axis at far off points?

A halved B doubled C quadrupled D remains unchanged

3. The strength of the magnetic field around an infinite current carrying conductor is :

A same everywhere B inversely proportional to the distance C directly proportional to the distance D None of these

4. A current carrying power line carries current from west to east. Then the direction of the magnetic field 2 m above it is :

A west to east B south to north C north to south D None of these

5. The force between two parallel current carrying conductors is F. If the current in each conductor is doubled, then the force between them becomes :

A 4F B 2F C F D \(\frac{F}{4}\)

6. How much force will be experienced by a moving charge in a magnetic field? The symbols have their usual meanings.

A \(\vec{F}\) = q(\(\vec{v}\).\(\vec{B}\)) B \(\vec{F}\) = \(\frac{q}{(\vec{v}.\vec{B})}\) C \(\vec{F}\) = \(\frac{q}{2}\)\((\vec{v}×\vec{B}\)) D \(\vec{F}\) = q(\(\vec{v}\)×\(\vec{B}\))

7. Which of the following is not a unit of magnetic induction?

A gauss B tesla C oersted D weber/metre²

8. The magnetic field produced by an / meter long straight (x cry thin) current (I) carry ing conductor at any point on itself is :

A zero B infinite C \(\frac{µ_0l}{4πl}\) D \(\frac{µ_0l}{2πl}\)

9. A charge + q is sent through a magnetic field. The force acting on it is maximum w hen the angle between the direction of motion of the charged particle and the magnetic field :

A 0° B 45° C 90° D 180°

10. An electron having mass 'm' and Kinetic energy E enters in uniform magnetic field B perpendicular, then its frequency will be:

A \(\frac{eE}{qmB}\) B \(\frac{2πm}{eB}\) C \(\frac{eB}{2πm}\) D \(\frac{2m}{eBE}\)