Question

`\underline{ \text{QUESTIONS}} :`

1. Write any three applications of electromagnetic waves. Complete the given ray diagram [ See the attached picture ]

2. The power of a bulb of car is 100 W. If 5A current flows through the filament of the bulb , calculate the voltage of the battery used in the car [ Ans : 20 V ] Please show your workings!

~Random/Irrelevant answers will be reported! ​

Answer 1

Step-by-step explanation:

1. Electromagnetic waves are used to broadcast radio and TV signals. It is also used for wireless charging cell phones. Cell phone itself uses electromagnetic waves for its cell signal.

See attached drawing for ray diagram.

2. Given: the power of a bulb of car is 100 W and 5A current flows through the filament of the bulb.

Power of a bulb is given by voltage * current.

So 100W = voltage * 5A

Voltage = 100/5 = 20V

Answer 2

Solution given:

any three applications of electromagnetic waves are:

1. Used for cooking purpose in microwave.
2. Used in RADAR system for aircraft navigation.
3. Used in communication.

2.

Solution given;

power [P]=100W

Current [I]=5A.

Voltage [V]=?

we have

P=IV

100=5*V

V=
`(100)/(5)`=20V

the voltage of the battery used in the car is 20V.