Question

The rating of the bulb is given as 100 watts and 240 volts find the resistance and work done if used for 5 hours​

Answer 1

Answer:

connected across 240v. How do you calculate the electrical power loss?

Ananda Krishnan

Answered 3 years ago

Firstly we calculate the resistance of the bulb,

According to Ohm’s Law

R=V/I Where,R=Resistance , V=Voltage ,I=Current..

100w at 220v, I=P/V.

=100/220=0.454Amp.

R=V/I; 220/0.454=484.56 ohms.

When it is connected to 240 Volts

I=V/R; 240/484.56=0.495 ~ 0.50 Amps.

Power consumed(P)=V×I; 240×0.50=120 W.

The bulb will consume 120 W at 240 Volts. 20W difference.

This is not a loss the bulb glows brighter than it used in 220 volts..

Explanation:

pls mark as brinlist

Answer 2

Given :-

Power (P) = 100 W

Potential difference (V) = 240 V

Time (t) = 5 hour

To Find :-

Resistance (R) = ??

Work done for 5 hours (W) = ??

Solution :-

We know

$\sf{P = \dfrac{(V)²}{R}}$

Or, $\sf{R = \dfrac{(V)²}{P}}$

$\sf{R = \dfrac{(240)²}{100}}$

$\sf{R = \dfrac{(57600}{100}}$

$\sf\fbox{R = 576 Ω}$

NOW ,

$\sf{W = \dfrac{P}{t}}$

$\sf{W = \dfrac{100}{5}}$

$\sf\fbox{W = 20 J }$