$$\tan \delta = \frac{B_v}{B_H}$$

Question 1

Which equation correctly describes the angle of dip (inclination) for a magnetic needle suspended freely, as shown in the first image?

Accepted Answer

$$	an \delta = \frac{B_v}{B_H}$$

Question 2

What is the physical significance of the angle of declination as shown in the third image?

Accepted Answer

It is the angle between the direction of the Earth's magnetic field and true north.

Question 3

In the context of electromagnetic waves (see image 8), which statement is correct?

Accepted Answer

The electric and magnetic fields are perpendicular to each other and to the direction of propagation.

Question 4

Which SI unit is used to measure the strength of a magnetic field, as referenced by the Tesla logo in image 10?

Accepted Answer

Tesla (T)

Question 5

According to the right-hand rule shown in image 11, what does the direction of the thumb represent?

Accepted Answer

The direction of the current or velocity of the charge.

Question 6

If a wire is carrying a current upward, as shown in image 12, what is the direction of the magnetic field around the wire?

Accepted Answer

It circles the wire in a direction given by the curled fingers of the right hand.

Question 7

Which equation describes the force on a current-carrying wire in a magnetic field?

Accepted Answer

$$F = IL 	imes B$$

Question 8

What is the main function of a magnetic field in steering charged particles, as used in lasers?

Accepted Answer

It exerts a force perpendicular to the velocity of the charged particle, causing it to change direction.

Question 9

Why does a magnetic field not do work on a moving charge?

Accepted Answer

Because the force is always perpendicular to the velocity, so $$W = F \Delta D \cos \phi is $$zero when $$\phi = 90^\circ.$$

Question 10

Which materials are considered ferromagnetic and can be magnetized, as described in the study materials?

Accepted Answer

Iron, nickel, cobalt, chromium dioxide, AlNiCo

Question 11

In nuclear fission (see images 4, 5, 6, and 7), what is the primary result of a neutron striking a $$^{235}U$$ nucleus?

Accepted Answer

The nucleus splits into smaller nuclei, releasing energy and additional neutrons.

Question 12

Which equation represents the nuclear fission reaction of $$^{235}U as $$shown in image 7?

Accepted Answer

$$^{235}_{92}U $$+ ^{1}$$_{0}n \$$rightarrow ^{90}$$_{36}Kr $$+ ^{143}$$_{56}Ba + 3$$^{1}$$_{0}n$$

Question 13

What is the effect of Earth's magnetic field on life, as described in the study materials?

Accepted Answer

It protects life by deflecting dangerous charged nuclear particles from the sun.

Question 14

If a charged particle moves perpendicular to a magnetic field, what type of motion will it exhibit?

Accepted Answer

Circular or semi-circular motion due to the centripetal force.

Question 15

Which equation describes the force on a moving charge in a magnetic field?

Accepted Answer

$$F = qv 	imes B$$

Question 16

What happens to the path of a neutron in a magnetic field?

Accepted Answer

It continues in a straight line, unaffected by the magnetic field.

Question 17

Which equation is used to calculate the work done by a force on a charge?

Accepted Answer

$$W = F \Delta D \cos \phi$$

Question 18

What is the relationship between the electric and magnetic fields in an electromagnetic wave?

Accepted Answer

They are equal in magnitude and perpendicular to each other.

Question 19

Which of the following is NOT a real-world application of magnetic fields as described in the study materials?

Accepted Answer

Increasing the speed of light in a vacuum.

Magnetic Fields and Magnetic Forces: Foundations and Applications

Study Guide - Practice Questions