Find the cost of electrical energy used by a lamp in 3.5hours if energy costs 17p/kWh and it uses 250W in 0.5h?

I think you need to use these formulas:
E = P x T
Cost = kWh x cost per kWh

Anonymous2011-04-15T07:08:26Z

Favorite Answer

If the lamp uses 250W in 0.5 hours, it uses 500W/hr = 0.5 Kw/hr

If the cost is 17p/kWh, your cost will be 17 x 3.5 x 0.5 = 29.75p