Question

• A lamp consumes 500j of electrical energy in 20s.find the electical energy consumed in unit if the lamp operates for 2hrs. for 15days

Answer 1

Solution:

Lamp consume energy in 20 sec = 500 J

Then,
$$\begin{gathered} Poweroflamp=\frac{w}{t}=\frac{500}{20}=25J/s \\ \mathit{P}\mathbf{}\mathbf{=}\mathbf{}\mathbf{25}\mathbf{}\mathit{J}\mathbf{/}\mathit{s} \end{gathered}$$

P = 25 Watt
or
P = .025 kW

If lamp operate 2 Hrs. Then, energy consumed by the lamp:

Energy = power x time take
Energy = .025 x 2
Energy = .05 kWh
Energy = 0.05 units

If the lamp used for 15 days then, the total energy consumed by the lamp:

Energy = 0.05 x 15 = 0.75 Units