A lamp is marked 12v, 240w how many joules does it consume in an hour and what is the current it passes ?

To calculate the energy consumed in joules by the lamp in an hour, we can use the formula:

Energy (joules) = Power (watts) x Time (seconds)

First, we need to convert the power from watts to joules per second:

1 watt = 1 joule/second

So, 240 watts = 240 joules/second

Since there are 3600 seconds in an hour, we can calculate the energy consumed in an hour:

Energy = 240 joules/second x 3600 seconds = 864,000 joules

Therefore, the lamp consumes 864,000 joules of energy in an hour.

To calculate the current passing through the lamp, we can use Ohm's Law:

Power (watts) = Current (amps) x Voltage (volts)

Given that the lamp is marked as 12V and 240W, we can rearrange the formula to solve for current:

Current = Power / Voltage
Current = 240W / 12V
Current = 20 amps

Therefore, the lamp passes a current of 20 amps.

Energy Consumption in an Hour:

Energy consumed = Power × Time
Power = 240 W
Time = 1 hour (3600 seconds)

Energy consumed = 240 W × 3600 s
Energy consumed = 864,000 J

Current Drawn:

Power = Voltage × Current
Voltage = 12 V
Power = 240 W

Current = Power / Voltage
Current = 240 W / 12 V
Current = 20 A

Therefore, the lamp consumes 864,000 J of energy in an hour and draws a current of 20 A.