Question

An electric bulb marked 40w and 200v is used in a circuit to supply 100v. now its power is

Answer 1

this is the answer to this question

Answer 2

Answer:

The power is 10 watt.

Explanation:

Given that,

Power of electric bulb p = 40 watt

Voltage v = 200 v

We need to calculate the resistance

Using formula of power,

$P=\dfrac{v^2}{R}$

$R=\dfrac{v^2}{P}$

Where, R = resistance

V = voltage

Put the value of v and P into the formula

$R=\dfrac{200\times200}{40}$

$R=1000\ ohm$

Now, when the voltage is 100 v

Using power formula again

$P=\dfrac{v^2}{R}$

$P=\dfrac{100\times100}{1000}$

$P=10\ watt$

Hence, The power is 10 watt.