Magnetic Flux Density

Q.

Which of the following statements are correct?

(A) Electric monopoles do not exist whereas magnetic monopoles exist.

(B) Magnetic field lines due to a solenoid at its ends and outside cannot be completely straight and confined.

(C) Magnetic field lines are completely confined within a toroid.

(D) Magnetic field lines inside a bar magnet are not parallel.

(E) χ = —1 is the condition for a perfect diamagnetic material, where χ is its magnetic susceptibility.

Choose the correct answer from the options given below :

1. (B) and (C) only

2. (B) and (D) only

3. (C) and (E) only

4. (A) and (B) only

Q.

Which of the following statements are true about magnetic flux density?

1. Magnetic flux density is the same throughout the length of the magnet

2. Magnetic flux density is greater at the poles of the magnet

3. Magnetic flux density doesn't depend on magnetic field lines

4. Magnetic flux density depend on magnetic field lines

Q. Statement 1 - Magnetic flux density is maximum at poles.
Statement 2 - Magnetic field lines are closed and continuous curves.

1. Both statement 1 and 2 are correct and statement 2 is the correct explanation of the statement 1.
2. Both statement 1 and 2 are correct and statement 2 is not the correct explanation of statement 1.
3. Statement 1 is incorrect and statement 2 is correct.
4. Both statements 1 and 2 are incorrect.

Q. The number of magnetic field lines passing normal to a unit surface area of a magnet, is known as .

1. magnetic field
2. magnetic flux
3. magnetic pole

Q.

If a bar magnet is moved to and fro near a copper coil then _____________.

1. Both (a) and (b)

2. the coil will undergo a chemical reaction

3. the current is induced in the coil

4. None of these

Q. Magnetic field can have only ____ direction at a particular point.

1. 0
2. 4
3. 1
4. 2

Q. Match the following:
$\begin{array}{cccc}& \text{Device}& & \text{Principle}\\ 1& \text{Electric Motor}& a& \text{Magnetic effect of current}\\ 2& \text{Dynamo}& b& \text{Increase or decrease the alternating voltage}\\ 3& \text{Transformer}& c& \text{Converts mechanical energy to electrical energy}\\ 4& \text{Electric Bell}& d& \text{Converts electrical energy to mechanical energy}\end{array}$

1. 1-a, 2-d, 3-b, 4-a
2. 1-a, 2-b, 3-c, 4-d
3. 1-d, 2-b, 3-c, 4-a
4. 1-d, 2-c, 3-b, 4-a

Q.

What is meant by saturation point?

Q.

_________ is a device which converts electrical energy into mechanical energy.

1. Speaker

2. Motor

3. Television

4. Electric Heater

Q. Which of the following area has a maximum magnetic flux density? (Assume both areas $A$ and $B$ to be equal)

1. $B$
2. $A$
3. $A$ = $B$
4. Cannot be determined

Q. Which figure indicates vibrations of sound produced by noise

1. (i) only
2. (i) and (ii)
3. (ii) only
4. None

Q.

What is meant by null point?

Q. The no. of magnetic field lines through a unit area normal to the magnet's surface is called:

1. Magnetic volume
2. Magnetic force
3. Magnetic field
4. Magnetic flux density

Q.

State the characteristics of magnetic lines of force.

Q.

If two horse-shoe magnets of equal strengths are connected as shown in the figure then where will be the new magnetic north pole?

1. near point 1

2. near point 2

3. near point 3

4. there will be no magnetic north-pole.

Q. Magnetic flux density is maximum at the __________ of a magnet.

1. centre
2. edges
3. poles
4. surface