electricity

Question 1

What is electric current?

Answer 1

Electric current is the flow of electric charges such as electrons

Question 2

What is the SI unti of electric current?

Answer 2

Ampere

Question 3

What is the SI unit of electric charge?

Answer 3

Coloumb

Question 4

What is a circuit diagram and why is it useful?

Answer 4

Circuit Diagram is a diagram which shows various electrical components within a circuit. It is made using electric symbold of those components. It is useful as it saves a lot of time and energy.

Question 5

Name any two heating effects of electric current?

Answer 5

1) Heating effect of electric current
2) Magnetic effect of electric current

Question 6

Describe heating effect of electric current.

Answer 6

When electric current passes through a resistance wire, it gets heated and produces heat. This the heating effect of electric current. In this process electrical energy gets converted into heat energy.

Question 7

Name any five devices which uses heating effect of electric current?

Answer 7

1) Immersion rod
2) Electric iron
3) Electric Toaster
4) Electric Geyser
5) Electric hair dryer

Question 8

Explain how room heater produces heat.

Answer 8

Room heater and other electrical appliances that works on the heating effect of electric current have elements inside them. When current is passed through this element which has high resistance get heated up and becomes red hot and gives heat

Question 9

What is circuit?

Answer 9

Circuit is the path along through which electric current flows.

Question 10

What is electric switch?

Answer 10

An electric switch is a device which is used to make or break a circuit (open or close)

Question 11

What is fuse? How does it prevent the appliance from being damaged or get possible fires?

Answer 11

A fuse is a safety device used in household circuits which prevents from getting possible fires and protects the appliance. There is a wire in fuse which has very low melting point. When high current exceeds high limit due to overloading or short- circuit and passes through the wire it melts and breaks the circuit due to which the high current does not reach further and thus prevents from getting possible fires and protects the appliance also.

Question 12

What is a battery?

Answer 12

A battery is a combination of two or more cells.

Question 12

To make a battery how the terminals should be connected?

Answer 12

To make a battery the positive/negative terminal of one cell should be connected to its opposite terminal (positive- negative, negative- positive).

Question 13

Of which material is the filament of the buld made up of?

Answer 13

Tungsten

Question 14

The fuse wire is made up of ______________ alloy.

Answer 14

tin-lead

Question 15

What is the full form of MCB?

Answer 15

Miniature Circuit Breakers

Question 16

Nichrome is an _________

Answer 16

alloy

Question 17

Which mark should be taken care of when byuing an electric appliance?

Answer 17

ISI

Question 18

MCBs work on ________________ effect of electric current.

Answer 18

magnetic

Question 19

Who first noticed the Magnetic effect of electric current?

Answer 19

Hans Christian Oersted

Question 20

Explain the magnetic effect of electric current.

Answer 20

When electric current passes through a current carrying wire, magnetic field is produced around it and the wire starts behaving lke a magnet. This the magnetic effect of electric current.

Question 21

What is an electromagnet?

Answer 21

An electromagnet is a temporary magnet which consists of coild of wire wound around a piece of iron. When electric current is passed through the wire, it produces a magnetic field around itself and the iron piece gets magnetized and behaves like a magnet. If any magnetic material is brough near this magnet it would get clinged to it and when switch is moved to the off position the iron piece loses its magnetism.

Question 21

The amount of heat produced depends of ___________, ________________ and _____________

Answer 21

Material, length and thickness

Question 21

Write the full form of CFL.

Answer 21

Compact Fluroscent Lamp

Question 22

State the uses of an electromagnet.

Answer 22

1) It is used to seperate iron pieces from a garbage heap or junk material.
2) It is used to seperate iron pieces that might have fallen accidentally in a patient’s eye.
3) It is used in transistor, toys etc.

Question 23

What does the thicker shorter parallel line represent in a circuit?

Answer 23

Negative terminal

Question 24

Explain the working of an electric bell.

Answer 24

An electric bell consists of an electromagnet, a contact screw, soft iron strip/armature, spring, hammer , battery, switch and a gong. There is a spring attached to a contact screw and when the switch is moved to the on position the electromagnet attracts the iron strip towards it and it strikes with the gong which produces a sound and the contact gets broken due to which the circuit gets broken and the iron strip come backs to its original position and again the circuit is complete and again the elctromagnet pulls towards it and this process stops anf continue stops and continue.