Electric Bell

Q. Which part makes the hammer strike the gong in an electric bell?

1. Cell
2. Gong
3. Magnet
4. Switch

Q.

Name the material used for making the armature of an electric bell. Give a reason for your answer.

Q. Which of the following devices use electromagnet?

1. Electric heater
2. Electric fuse
3. Bulb
4. Electric bell

Q. What is mechanical strength

Q.

How is the working of an electric bell affected, if alternating current be used instead of direct current ?

Q. Draw a neat and labelled diagram of an electric bell and also describe it’s working.
$\left[7\text{marks}\right]$

Q.

Electromagnets are not used in

1. Electric bell

2. Refrigerator

3. Telephone

4. Galvanometer

Q.

What will be the effect on the working of an electric bell if instead of a direct current, an alternating current is used ?

Q.

How does an electrical slip ring work?

Q. Which of the following uses electromagnets to operate?

1. Maglev train
2. Electric train
3. Cargo train
4. Coal train

Q.

The striker of the electric bell moves due to attractive force of the electromagnet.

Say True or False.

1. True

2. False

Q.

Name one device that uses an electromagnet.

Q.

Sound is produced in an electric bell, when:

1. the striker hits the gong

2. the electromagnet is switched on

3. the striker moves away from the gong

4. none of the above

Q. The following appliances use _______ effect of electric current.

1. chemical
2. magnetic
3. mechanical
4. heating

Q. What do you think the mechanical hand was trying to do?

Q.

For the following devices:

I: Fuse

II: Electric Bulb

III: Electric Bell

Select the correct option.

1. III works on the principle Heating effect of current

2. I and III work on the principle of Magnetic effect of current

3. I and II work on the principle of Heating effect of current

4. II and III work on the principle Magnetic effect of current

Q. An electric bell works on the ______ of electric current.

1. Heating effect
2. Magnetic effect
3. Chemical effect
4. (a) and (c) above.

Q. Which of the following energy conversion takes place in an electric bell?

1. Mechanical energy to sound energy

2. Electrical energy to sound energy

3. Electrical energy to mechanical energy

4. Electrical energy to magnetic energy

Q.

Select the correct option:

1. A – Striker, B- Contact Screw, C – Electromagnet, D - Gong

2. A – Gong, B- Contact Screw, C – Electromagnet, D - Striker

3. A – Striker, B- Electromagnet, C –Contact Screw, D - Gong

4. A – Striker, B- Gong, C – Contact Screw, D – Electromagnet

Q. Pick the devices that contain electromagnets.

1. MRI scanner
2. Headphones
3. Maglev train
4. Loudspeaker
5. Electric iron
6. Electric bell
7. Steam engine
8. Motor

Q. What makes and breaks the circuit in an electric bell?

1. Contact screw
2. Electromagnet
3. Striker
4. Gong

Q. Label the parts of the electric bell given below.

1. Electromagnet
2. Gong
3. Contact screw
4. Striker

Q.

How is the working of an electric bell affected, if alternating current be used instead of direct current ?