Magnetic Induction

Q.

How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.

Q.

State the two methods of making a magnet.

Q. Induced magnetism is the temporary magnetism.

1. True
2. False

Q.

Explain how a magnet gets demagnetized when an alternating current is passed through a coil in which the magnet is placed.

Q. Which of the following actions will not make a magnet lose its magnetic properties?

1. Dropping a magnet from a certain height
2. Hammering a magnet
3. Passing electric current
4. Heating a magnet

Q. The temporary magnetism acquired by a magnetic material in presence of a magnet is called _______.

1. temporary magnetisation
2. magneto
3. magnetic induction
4. magnification

Q.

Natural magnets are stronger than artificial magnets.

1. True
2. False

Q.

Magnetic induction occurs when a piece of magnetic material comes near a magnet.

1. True
2. False

Q.

Can we magnetize an iron piece permanently by the method of magnetic induction?

Q.

What is magnetic induction? What type of magnets can be made by this method- temporary or permanent?

Q. Which of these material(s) will behave like a magnet when it comes in contact with a bar magnet?

1. Iron
2. Steel
3. Silver
4. Cobalt

Q.

Rough handling destroys the ______ properties of a magnet.

Q.

Lode stone is an example of:

1. natural magnet

2. artificial magnet

3. electromagnet

4. none of these

Q.

Magnets attract magnetic substances; this property is used in refining iron ore to separate iron from other impurities.

1. True
2. False

Q. By inserting an iron core in a coil carrying current, the strength of its magnetic field will :

1. increase
2. decrease
3. remain Same
4. become Zero

Q. By rubbing against a bar magnet how it can be turned into magnet

Q.

A magnetic material near a magnet possesses _______.

1. artificial magnetism

2. permanent magnetism

3. induced magnetism

4. electromagnetism

Q. A freely suspended bar magnet would align itself in the ______ direction.​

1. north-south
2. east-west
3. north-west
4. south-east

Q. Aquil used a strong magnet to stroke the iron nail fifty times in the same direction continuously. After stroking, he wanted to test it by bringing a compass near the tip of the nail. Which one of the following diagrams shows the correct observation?

1. 
2. 
3. 
4. 

Q.

Difference between magnetising by single touch method and by double touch method?

Q.

Arrange the following statements in sequential order to magnetize a steel bar using the single touch method.

(A) Once, it has reached the other end, lift the magnet away from the steel bar and again bring it to the starting point.

(B) Keep a steel bar to be magnetized on a wooden table.

(C) Take a strong magnet and bring one of the poles of the magnet near one end of the steel bar and gently rub from one end to the other end.

(D) Repeat this process several times.

1. BCAD

2. BACD

3. CBDA

4. CABD

Q. State whether true or false :
Magnetization by electric current method creates more powerful magnets than other methods of magnetization.

1. True
2. False

Q. The north-south polarities of an electromagnet can be found easily by using:

(a) Fleming's right-hand rule
(b) Fleming's left-hand rule
(c) Clock face rule
(d) Left-hand thumb rule

Q. When a magnetic substance chemically combines with other elements to form compounds, it is quite possible that the resulting compound is:

1. More magnetic
2. Not very magnetic
3. Diamagnetic
4. Antiferromagnetic

Q. Describe briefly two methods of making a magnet. Draw a labelled sketch to illustrate the method.

Q. The magnetic induction method can be used to turn a piece of metal into a magnet, temporarily only.

1. True
2. False

Q. Identify the correct method to turn a soft iron into a magnet.

1. Rubbing one pole of magnet in one direction
2. Rubbing one pole of magnet in both direction
3. Rubbing with a non-magnetic material
4. Keeping another magnet on top of it

Q.

Why do we say that "induction precedes attraction"?