A bulb marked 240V, 40W is used for 30 minutes. Calculate the heat generated
Question 1 Report
A bulb marked 240V, 40W is used for 30 minutes. Calculate the heat generated
Answer Details
The formula for calculating electrical energy is given by:
E = P x t
Where E is the energy in joules, P is the power in watts, and t is the time in seconds.
Firstly, we need to convert the time of 30 minutes to seconds.
30 minutes = 30 x 60 seconds = 1800 seconds
The power of the bulb is given as 40W, and the voltage is given as 240V. We can use these values to calculate the current (I) flowing through the bulb:
Power (P) = Voltage (V) x Current (I)
Current (I) = Power (P) / Voltage (V)
Current (I) = 40 / 240 = 0.1667 A (to 4 decimal places)
Now we can use the formula for energy to calculate the heat generated:
E = P x t
E = 40 x 1800
E = 72000 J
Therefore, the answer is 72000J. So, the correct option is 4) 72000J.
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