Question

The energy used by an appliance which operates at 240 volts at 15 amp for 4 hr. is A. 0.92 kwhr. B. 3.45 kwhr. C. 14.4 kwhr. D. 60.0 kwhr

Answer 1

Answer:

C. 14.4 kwhr.

Explanation:

To calculate the energy used by appliance first calculate the power. The formulae for calculating power(P) is $P= I \times V$, where V stands for voltage and I stands for current.

In the given problem,  V = 240 volts and I = 15 amp. Therefore,

$P=240 \times 15 =3600\ watt(w) = 3.6\ kw$

Now, formulae for calculating energy used i.e. work(W) is $W = P\times t$, where t is the time.

In the given question time is 4 hr. Therefore energy used will be,

Energy used (W) = $3.6\times4 =14.4\ kwhr$.