A 12 HP motor has to be operated 8 hours / day . How much will it cost at the rate of 50 paisa / kWh in 10 days

Options

A. Rs.350 /-
B. Rs.358/-
C. Rs.375/-
D. Rs.397/-

Answer

B

Explanation

If a motor of 12HP works for 10 days at the rate of 8 hr/day then energy consumption = power `xx` time
`=12 xx 746 (J)/(sec)xx (80 xx 60 xx 60)sec`
`=12 xx 746 xx 80 xx 60 xx 60J= 2.5 xx 10J`
Rate of energy `=50 ("paisa")/(kWh)`
i.e. `3.6 xx 10^(6)J` energy cost 0.5Rs
So `2.5 xx 10J` energy cost `= (2.5 xx 10^(9))/(2 xx 3.6 xx 10^(6))= 358` Rs