Question

an electric heater rated 600w operates 6h/day. find the cost of energy to operate it for 30 days at rs.6.00 per unit

Answer 1

Answer:

Rs. 648

Explanation:

Power=600w or 0.6kw

time for 1 day =6hrs

commercial unit =0.6×6=3.6kwh

for 30 days=3.6×30=108kwh

per day is Rs6=108×6=Rs648

Answer 2

The cost energy to operate the electric heater is Rs. 648/- .

The electric heater is rated as 600 W

∴ Maximum power it can deliver = 600 W = 0.6 KW

We know,

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

The heater operates 6 h/ day.

It is operated for 30 days.

∴ Total time = (6 × 30 ) hr

                    = 180 hr

From the equation,

Energy = Power × Time

or, Energy = 0.6 × 180 KJ

                 = 108 KJ

Commercially, Per unit price = Rs. 6/-

∴ Total commercial cost = Rs. (108 × 6) /-

                                        = Rs. 648/-

So, Total commercial cost will be Rs. 648/- .