Question

An electric iron draws a current of $15A$ from a $220V$ supply. What is the cost of using iron for $30$ min everybody for $15$ days if the cost of unit is 2 rupees?$(1unit=1kWh)$

• A. Rs $49.50$
• B. Rs $60$
• C. Rs $40$
• D. Rs $10$

Answer 1

The correct option is A Rs $49.50$

Current, $I=15A$

Voltage, $V=220V$

Time, $t=30min=\frac{30}{60}=0.5h$

Number of days $=15days$

Total time, $T=15\times 0.5=7.5h$

Cost per unit $=\text{Rs}2$

$Power=\frac{Energy}{Time}$

$Energy=Power\times Time$

$E=V.I\times T$

$E=220\times 15\times 7.5$

$E=24750Wh=24.75KWh$

Cost for 15 days $=24.75\times 2=Rs49.5$