Answer:
a) 8 cents
b) 25.6 cents
c) 2.4 cents
Explanation:
Given:
Cost of electricity = 8 cents/kWh
Total cost = Wattage ×Time × Electricity cost
a) cost of running a lamp of 100 W for 10 h will be
Energy consumed = 100 W ×10 h = 1000 Wh or 1 kWh [1 kW = 1000 W]
Total cost = Energy consumed × electricity cost
⇒Total cost = 1 kWh × 8 cents/kWh = 8 cents
b) cost of running a TV of 400 W for 8 h will be
Energy consumed = 400 W × 8 h = 3200 Wh or 3.2 kWh
Total cost = Energy consumed × electricity cost
⇒Total cost = 3.2 kWh × 8 cents/kWh = 25.6 cents
c) cost of running a microwave of 1200 W for 15 min will be
Energy consumed = 1200 W ×[tex]\frac{15}{60}[/tex] = 300 Wh or 0.3 kWh [1h = 60 min]
Total cost = Energy consumed × electricity cost
⇒Total cost = 0.3 kWh × 8 cents/kWh = 2.4 cents