Magnetic Flux Questions

The number of magnetic field lines passing through a given closed surface gives the magnetic flux. Magnetic flux is represented by ‘B’. Magnetic flux is commonly denoted using the Greek letter Φ or ΦB. The CGS unit of magnetic flux is the Maxwell, and the SI unit of magnetic flux is the Weber (Wb).

Magnetic flux is usually measured with a flux meter.

• The fundamental unit is Volt-seconds.
• The CGS unit is Maxwell.

Read more: Magnetic Flux

Important Magnetic Flux Questions with Answers

1. What is the SI unit of magnetic flux?

1. Maxwell
2. Weber
3. Gauss
4. Dyne

Answer: b) Weber

Explanation: The SI unit of magnetic flux is Weber (Wb).

2. The CGS unit of magnetic flux is ______

1. Dyne
2. Emu
3. Erg
4. Maxwell

Answer: d) Maxwell

Explanation: The CGS unit of magnetic flux is maxwell.

3. The CGS unit of magnetic flux density is _____

1. Maxwell
2. Erg
3. Gauss
4. Dyne

Answer: c) Gauss

Explanation: Gauss is the CGS unit of magnetic flux density.

4. The magnetic permeability unit is ______

1. Maxwell
2. Tesla
3. Gauss
4. Dyne

Answer: b) Tesla

Explanation: Tesla is the unit of magnetic permeability.

5. What is the formula to find the magnetic flux?

1. \(\begin{array}{l}\phi _{B}=B-A=B-A\; cos \; \Theta\end{array} \)
2. \(\begin{array}{l}\phi _{B}=B.A=BA\; cos \; \Theta\end{array} \)
3. \(\begin{array}{l}\phi _{B}=B+A=B+A\; cos \; \Theta\end{array} \)
4. \(\begin{array}{l}\phi _{B}=B/A=B/A\; cos \; \Theta\end{array} \)

Answer: b)

Explanation: The formula to calculate the magnetic flux is

Where,

ΦB is the magnetic flux.

B is the magnetic field.

A is the area.

θ the angle at which the field lines pass through the given surface area.

6. The total number of magnetic field lines passing through a given area normally is referred to as _____.

1. Magnetic density
2. Magnetic line density
3. Magnetic flux
4. Magnetic susceptibility

Answer: c) Magnetic flux

Explanation: Magnetic flux gives the net magnetic field lines passing through a given area normally.

7. State true or false: The movement of charged particles is the main cause of magnetism.

1. TRUE
2. FALSE

Answer: a) TRUE

Explanation: Motion of electrically charged particles induced magnetic field.

8. Magnetic field outside a solenoid is ______

1. 1
2. 0
3. -1
4. Infinity

Answer: b) 0

Explanation: There are no magnetic field lines outside a solenoid. Hence the magnetic field is zero.

9. Magnetic flux is denoted by ______

1. \alpha
2. \beta
3. Φ
4. \vartheta

Answer: c) Φ

Explanation: Magnetic flux is denoted by Φ or ΦB.

10. The magnetic flux is a _______

1. Vector quantity
2. Scalar quantity
3. Neither scalar nor vector
4. Dimensionless quantity

Answer: b) Scalar quantity

Explanation: Since it indicates the magnitude of the magnetic field lines and not the direction, it is considered a scalar quantity.

Watch the video below to know about Magnetism and Matter.

Practice Questions

1. What is magnetism?
2. Explain the various units of magnetic flux.
3. What is magnetic flux density?
4. What is a magnetometer?
5. Define magnetic permeability.