65
Electricity
Exercises
swer the following in not more than 20 words.
What do you need to apply across a bulb to cause a current to flow through it?
Why does a bulb get warmer than the wires that connect it to a battery?
A magnetic needle gets deflected when brought near a current-carrying conductor. What does
this show?
What happens when you place an iron nail in a current-carrying coil?
Why do we use a soft iron core in an electromagnet?
Name four devices that use the heating effect of electric current.
Mention four applications of electromagnets.
swer the following in not more than 40 words.
What is a circuit diagram? Draw the circuit diagram of a torch which works on three cells.
Identify the following symbols. Also mark the positive and negative terminals in the symbol for
the cell.
=
S
the magnitude of
Answers
Answer:
please thanks me all ans
1. We need to apply voltage across a bulb to cause a current to flow through it .
2.Since the resistance of the bulb is much more than the resistance of the wire ,the bulb gets hotter and wire stays cool.
3. Magnetic needle gets deflected when it is brought near a current carrying conductor it shows that the current carrying conductor is good conductor of electricity.
4. when the iron strip is contact with the screw the current flows through the coil.which becomes an electromagnet. It then pulls the iron strip in the process the harmer of the end of the strip strikes the going of the bell the produce a sound .
5. Electromagnets are made up of soft iron because soft iron has low retenticity and low corive force .Soft iron is a magnetic material.
6. The heating effect of electric of electric current is utilized in the working of electrical heating appliances such as electric room heater , electric iron , electric toaster, electric kettle, water heater etc.
7.Motors and generators, transformers , pickups, relays , Electric bells and buzzers.
8. question answer up in diagram.
