Question

you are given four bulbs of 25W,40W,60Wand 100W of power,all operating at 230V which of them has the lowest resistance​

Answer 1

Answer:100w has lowest resistance

Explanation:P=V^2/2R

25W=1058 resistance

40W=661.25

60W=440.8

100W=274.5

Answer 2

Answer:

The power of 100 W bulb has lowest resistance.

Explanation:

Given that,

Power of first bulb = 25 W

Power of second bulb = 40 W

Power of third bulb = 60 W

Power of fourth bulb = 100 W

Voltage = 230 V

We need to calculate the lowest resistance,

Using formula of power

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

The power is inversely proportional to the resistance.

The power will maximum of the bulb then the resistance will be lowest.

We need to calculate the resistance of first bulb

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

Put the value into the formula

$R=\dfrac{230^2}{25}$

$R=2116\ \Omega$

For second bulb,

$R=\dfrac{230^2}{40}$

$R=1322.5\ \Omega$

For third bulb,

$R=\dfrac{230^2}{60}$

$R=881.6\ \Omega$

For fourth bulb,

$R=\dfrac{230^2}{100}$

$R=529\ \Omega$

Hence, The power of 100 W bulb has lowest resistance.