Question

Calculate the no. of 'units' of electricity consumed for a month for the following details of electrical components in a household. Consider all the given components are used for 10 hours a day. (Take 1 month = 30 days)

Home Appliance	Wattage
6 ceiling fans	60 W each
4 CFLs	15 W each

• A. 12600
• B. 1260
• C. 126
• D. 12.6

Answer 1

The correct option is C 126

Power consumed by one ceiling fan, $P_f=60W$
Power consumed by all the 6 ceiling fans:
$P_1=6P_f$
$P_1=6\times 60=360W$

Power consumed by one CFL, $P_c=15W$
Power consumed by all the 4 CFLs:
$P_2=4P_c$
$P_2=4\times 15=60W$

All equipments run for duration, $t=10\text{hr}$
Total power consumed in a day:
$P_d=t(P_1+P_2)$
$P_d=10\times (360+60)=4200Wh$
$P_d=4.2kWh=4.2\text{units}$

For one month, total power consumed is:
$P=30P_d$
$P=4.2\times 30=126\text{units}$