Question

How much will be the power of a 220 v, 40 w electric bulb working at 110 v

Answer 1

Answer:

10 watt

Explanation:

hey buddy here is ur answer

....

se

$p = v {}^{2} \div r$

where r is resistance of bulb

now actual power of bulb is

$r = v {}^{2} \div p$

that is

$220 \times 220 \div 40 \: ohm$

that is

that is

$p = 110 \times 110 \times 40 \div 220 \times 220 \\ \\ thats \: i s \: equal \: to \: 10watt$

Answer 2

SOLUTION:-

Given

• v = 220

• p = 40w

Answer

• R= 1210 ohm

• p=10w

Explanation

Resistance of the electric bulb

Power of electric bulb is Given by

p = v²/R

putting values >>

• p = v²/R

=>> 40 = (220)² / R

=>> 40 R = 220×220

=>> 40R = 48400

=>> R = 48400/40

=>> R= 1210ohm

If the voltage becomes 110v

• P = v²/R

=>> p= (110)² / 1210

=>> p= 12100/1210

=>> p= 10w

Hence

• R= 1210 ohm

• p= 10w

_______________________________