Question

The current through a 12 V tungsten filament lamp connected to a 12 V accumulator of negligible resistance id is 3.0 A, calculate:
• Resistance of the filament
• Power of the lamp
• Electrical energy in KWh consumed in 5 hours.​

Answer 1

Answer:

a) Resistance :

by ohms law we know that V = IR

so  12 = 3 x R

=> 4 = R

therefore the resistance is 4 ohm

b) Power :

P = v2/r

= 144/4

= 36 watt

c) now to covert watt to kw we have to divide it by 1000 and to find how much energy is consumed we multiply it by no of hours so

= 36/1000 kW

= 0.036

now , 0.036 X 5 = 0.180