Magnetic Field Due to Current in a Solenoid

Q.

Choose the correct option: The magnetic field inside a long straight solenoid-carrying current.

1. is zero

2. decreases as we move toward its end

3. increases as we move toward its end

4. is the same at all points

Q.

Why does electric current produce a magnetic field?

Q.

The material suitable for making electromagnets should have:

1. High retentivity and high coercivity

2. High retentivity and low coercivity

3. Low retentivity and low coercivity

4. Low retentivity and high coercivity

Q.

Explain the working of a solenoid

Q.

A constant current $I$ is maintained in a solenoid. Which of the following quantities will not increase if an iron rod is inserted in the solenoid along its axis?

1. the magnetic field at the centre.

2. self-inductance of the solenoid.

3. magnetic flux linked with the solenoid.

4. rate of Joule heating.

Q.

How placing an iron core in a solenoid can increase the strength of an electromagnet?

Q.

A square coil of side $25cm$ having $1000$ turns is rotated with an uniform speed in a magnetic field about an axis perpendicular to the direction of the field. At an instant $t$, the emf induced in the coil is $e=200\sin 100\pi t$. The magnetic induction is

1. $0.50T$

2. $0.02T$

3. ${10}^{-3}T$

4. $0.1T$

5. $0.01T$

Q.

What is the difference between a solenoid and an electromagnet?

Q.

State two ways by which the magnetic field due to a current carrying solenoid can be made stronger.

Q.

The diagram shows a small magnet placed near a solenoid AB with its north pole N near the end A. Current is switched on in the solenoid by pressing the key K.
(a) State the polarity at the ends A and B.
(b) Will the magnet be attracted or repelled? Give a reason for your answer.

Q.

Why does a current carrying freely suspended solenoid rest along a particular direction? State the direction in which it rests.

Q.

A solenoid is used as a temporary magnet (an electromagnet). Why is a soft iron core preferred as compared to steel core?

1. Soft Iron retains its magnetism when current is switched off whereas Hardened steel loses its magnetism

2. Soft Iron quickly loses its magnetism when current is switched off whereas Hardened steel retains its magnetism

3. Soft Iron creates a fluctuating magnetic field when current flows through it whereas Hardened steel retains its magnetism

4. Soft Iron quickly loses its magnetism when current is switched off whereas Hardened steel has a weak temporary magnetic field

5. Soft Iron has a fixed magnetism when whereas Hardened steel has fluctuating magnetism

Q.

What is an example of magnetic energy?

Q.

The north pole of a long bar magnet was pushed slowly into a short solenoid connected to a galvanometer.

The magnet was held stationary for a few seconds with the north pole in the middle of the solenoid and then withdrawn rapidly. The maximum deflection of the galvanometer was observed when the magnet was :

(a) moving towards the solenoid (b) moving into the solenoid

(c) at rest inside the solenoid (d) moving out of the solenoid

Q.

The magnetic field inside a toroidal solenoid is

Q.

In a current-carrying long solenoid, the magnetic field produced does not depend upon

Q.

The diagram shows a spiral coil wound on a hollow cardboard tube AB. A magnetic compass is placed close to it. Current flows through the coil on closing the key.

(a) What will be the polarity at the ends A and B?

(b) How will the compass needle be affected? Give reason.

Q.

What effect will there be on a magnetic compass when it is brought near a current carrying solenoid?

Q. Question 10
The strength of magnetic field inside a long current carrying straight solenoid is

(a) more at the ends than at the centre
(b) minimum in the middle
(c) same at all points
(d) found to increase from one end to the other

Q.

What is the way to detect the polarity of a current carrying solenoid?

Q.

Does a capacitor convert $AC$ to $DC$$?$

Q.

How can a solenoid be used to magnetise a steel bar? [1 MARK]

Q.

State whether the following statement is true or false :

The magnetic field inside a long circular coil carrying current will be parallel straight lines.

Q.

The magnetic field lines in the middle of the current-carrying solenoid are :

(a) circular

(b) spirals

(c) parallel to the axis of the tube

(d) perpendicular to the axis of the tube

Q.

What is the shape of a current-carrying conductor whose magnetic field pattern resembles that of a bar magnet ?

Q. A solenoid has 500 turns of wire in its 40 cm length. If the current in the wire is 1 A, then magnetic field at the centre of the solenoid is

1. 
   Zero
2. 
   $1250{\mu }_{0}T$
3. 
   $\pi T$
4. 
   ${\mu }_{0}T$

Q.

How is the magnetic field due to a solenoid carrying current affected if a soft iron bar is introduced inside the solenoid?

Q.

The north pole of a bar magnet is rapidly introduced into a solenoid at one end (say a). which of the following statements correctly depicts the phenomenon taking place

1. No induced emf is developed

2. The end A of the solenoid behave as south pole

3. The end A of the solenoid behave as north pole

4. The end A of the solenoid acquires positive potential

Q.

When a soft iron core is inserted in a coil, the strength of the magnetic field:

1. Decreases

2. Increases

3. Remains the same

4. Will become 0

Q.

If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be :

(a) west pole (b) south pole (c) south pole (d) west pole