5. Magnetism and matter

The earth behaves as a magnet with magnetic field pointing approximately from the geographic

• (a) North to South

• (b) South to North

• (c) East to West

• (d) West to East

The strength of the earth’s magnetic field is

• (a) constant everywhere.

• (b) zero everywhere.

• (c) having very high value.

• (d) vary from place to place on the earths surface.

3. Which of the following is responsible for the earth’s magnetic field?

• (а) Convective currents in earth’s core

• (b) Diversive current in earth’s core.

• (c) Rotational motion of earth.

• (d) Translational motion of earth.

Which of the following independent quantities is not used to specify the earth’s magnetic field?

• (a) Magnetic declination (θ).

• (b) Magnetic dip (δ).

• (c) Horizontal component of earth’s field (B_H).

• (d) Vertical component of earth’s field (B_V).

The vertical component of earth’s magnetic field . at a place is √3 times the horizontal component the value of angle of dip at this place is

• (a) 30°

• (b) 45°

• (c) 60°

• (d) 90°

The angle of dip at a certain place where the horizontal and vertical components of the earth’s magnetic field are equal is

• (a) 30°

• (b) 75°

• (c) 60°

• (d) 45°

Magnetic moment for solenoid and corresponding bar magnet is

• (a) equal for both

• (b) more for solenoid

• (c) more for bar magnet

• (d) none of these

A current carrying loop is placed in a uniform magnetic field in four different orientations as shown in figure. Arrange them in the decreasing order of potential energy.

• (a) 4, 2, 3,1

• (b) 1, 4, 2, 3

• (c) 4, 3, 2,1

• (d) 1, 2, 3, 4

The net magnetic flux through any closed surface, kept in a magnetic field is

• (a)

• (b)

• (c)

• (d)

Point out the correct direction of magnetic field in the given figures.

• (a)

• (b)

• (c)

• (d)