# Magnetism Exe-10B Short Ans Concise Physics ICSE Class 9 Selina Solutions

Magnetism Exe-10B Short Ans Concise Physics ICSE Class 9 Selina Solutions.  Answer on Electro- Magnet Important questions for exam preperation.  Visit official Website CISCE for detail information about ICSE Board Class-9 Physics.

## Magnetism Exe-10B Short Ans Concise Physics ICSE Class 9 Selina Solutions

 Board ICSE Class 9 Subject Physics Writer / Publication Concise selina Publishers Chapter-10 Magnetism Exe-10B Electro- Magnet and its Uses Topics Solution of Exe-10B Short Answer Type Academic Session 2024-2025

### Electro- Magnet and its Uses

Magnetism Exe-10B Short Ans Concise Physics ICSE Class 9 Selina Solutions

##### Question-1: What is an electromagnet?

Answer- Electromagnets are made out of a coil of wire (wire curled in series). This is more effective in producing a magnetic field than just a wire running straight. This effect can be strengthened by winding a wire tightly around a powerful core made of magnetic material, such as iron.

##### Question-2: Fig. 10.18 shows alongside a coil wound around a soft iron bar XY.

(a) State the polarity at the ends X and Y as the switch is pressed.
(b) Suggest one way of increasing the strength of the electromagnet so formed.

(a)=>X-south pole, Y-north pole.

(b)=> By increasing the current in the coil.

##### Question-3: State two ways through which the strength of an electro magnet can be increased.

Answer- Electromagnet is a soft iron core made into a magnet by passing electric current through a coil surrounding it. There are two methods by which we can increase strength of magnetic field are:

1=> By increasing the number of turns of wire in the coil.

2=> By increasing the current flowing the coil.

##### Question-4: State two advantages of an electromagnet over a permanent magnet.

Answer- Following are the advantages of an electromagnet over a permanent magnet:

1=>An electromagnet can produce a strong magnetic field.

2=>The strength of the magnetic field of an electromagnet can easily be changed by changing the current in its solenoid.

##### Question-5: How is the working of an electric bell affected, if alternating current is used instead of direct current?

Answer- If an a.c. source is used in place of battery, the core of electromagnet will get magnetized, but the polarity at its ends will change. Since attraction of armature does not depend on the polarity of electromagnet, so the bell will still ring on pressing the switch.

##### Question-6: Name the material used for making the armature of an electric bell. Give a reason for your answer.

Answer- the material used for making the armature of an electric bell is Soft iron. The reason for using this material is its property as it can be magnetised and demagnetised very easily.

—:  end of Magnetism Exe-10B Short Ans Electr-Magnet Concise Physics ICSE Class 9 Selina Solutions.  :—

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