Question

A lamp rated 100w at 220v is connected to main supply .what is the current?

Answer 1

Answer:

0.45 Amperes

Explanation:

Given :

• Power rating of the lamp = P = 100 watts

• Potential difference or voltage across the circuit = V = 220 volts

To find :

• Current drawn by the circuit

P=V²/R

100=220²/R

100R = 48,400

R=48,400/100

R=484 ohms

Now using the ohms law:

V=I×R

220=I×484

I=220/484

I=0.45 Amperes

The current flowing through the circuit is equal to 0.45 Amperes

Formulas used:

• P=V²/R

• V=I×R

Answer 2

Given ,

Electric power (P) = 100 w

Potential difference (v) = 220 v

We know that ,

$\sf \large \fbox{Electric \: power \: (P) =VI }$

Thus ,

100 = 220 × I

I = 0.45 amp

$\sf \therefore \underline{The \: current \: is \: 0.45 \: amp \: }$