Physics – Class 12 Practice Test 5

1. Ferromagnetic materials does not show hysteresis.

False

True

2. Voltage sensitivity and current sensitivity are related.

True

False

3. The galvanometer shows deflection even when the bar magnet is stationary.

False

True

4. Pick out the expression for galvanometer constant from the following?

\(\frac {1}{G} \, = \, \frac {k}{NAB}\)

G = \(\frac {NAB}{k}\)

G = k × NAB

G = \(\frac {k}{NAB}\)

5. A bar of length 2m is said to fall freely in a magnetic field of magnitude 50 T. What is the motional emf in the bar when it has fallen 40 meters?

700 V

2100 V

1400 V

2800 V

6. Calculate the surface integral of a magnetic field over a surface.

Equal to its magnetic flux through that surface

Minimum

Zero

Maximum

7. Pick out the material that cannot be used to make permanent magnets.

Aluminum

Copper

Steel

Zinc

8. The line of force in a magnetic field represents the direction at each point that a magnetic needle placed at the point takes up. Do they also represent the direction of the force on a moving charge at each point?

Represent circular motion

Not possible

Represents translatory motion

Represent tangential motion

9. When is the magnetic flux said to be positive?

θ = 180^o

θ = 360^o

θ = 0^o

θ = 90^o

10. Both magnetization and magnetic intensity have the same unit.

True

False