Question

What will be the resistance of a lamp, rated for 220V-500W and connected across a 110 volt supply? Please tell the answer with EXPLANATION...

Answer 1

Answer:

To calculate this, first we need to calculate the resistance of he bulb so,

P = (V^2)/R

500 = (220^2)/R

R = 484/5

R = 96.8 …(i)

so when voltage is 110

P = (110^2)/96.8

P = 121000/968

P =125 Watt

Answer 2

Given: Power = 500W

          Voltage of lamp = 220V

          Voltage supply = 110V

To find: Resistance of the lamp

Solution:

Power of lamp is represented by an equation, P = V²/R

Putting the values in the equation, 500 = (220)² / R

                                                         , R = (220×220)  / 500

                                                           R = 96.8 Ω

Therefore, the resistance of the lamp is 96.8 Ω

• Power is equal to the voltage difference across the element multiplied by the current.
• SI unit of power is Watt.