Question

Study the table given below and find the value of '$A$' and '$B$'.

Device	Power	Time of working (hours)	Energy consumed (in kWh)
Incandescent bulb	$60$ $W$	$A$	$0.6$
CFL	$B$	$9$	$0.18$

Answer 1

The energy is given in terms of power as
$E=P\times t$ where $P=Power$ and $t=time$
For finding $A$:
$t=\frac{E}{P}=\frac{0.6\times {10}^{3}Wh}{60W}=10h$
For finding $B$:
$P=\frac{E}{t}=\frac{0.18\times {10}^{3}Wh}{9h}=20W$