6.4 Calculate the cost of electricity consumption

A toaster, rated 1500 W 240 V, is switched on for 15 minutes. Calculate the energy used.

• 3600 J

• 22 500 J

• 216 000 J

• 1 350 000 J

Tags

NGSS.HS-PS3-1

An air-con, rated 1.8 kW 240 V, is switched on for 10 minutes. Calculate the energy used.

• 1 080 000 J

• 144 000 J

• 2400 J

• 18 J

Tags

NGSS.HS-PS3-1

The electrical energy used by a fan for 4 minutes is 170 kJ. Calculate the power of this fan in W.

• 42.5

• 42500

• 708

• 0.708

A television rated 1.2 kW , 240 V is connected to a 240V electricity supply. Calculate curent that flows through the television.

• 5 A

• 2.5 A

• 0.005

• 1.0 A

An oven rated 750 W, 220 V is switched on for 45 minutes. Ho much electrical energy is used by the oven?

• 3.4 J

• 165000 J

• 33750 J

• 2025000 J

Tags

NGSS.HS-PS3-1

An oven rated 750 W, 220 V is switched on for 45 minutes. Calculate the cost of energy that is used by the oven if the cost per 1 unit is 30 sen?

• 3 sen

• 17 sen

• 16875 sen

• 4 sen

Tags

NGSS.HS-PS3-1

A 5kW electric cooker is used for 55 minutes to cook. Calculate the cost of electrical energy used if the rate per unit is 50 sen.

• RM 0.23

• RM 230

• RM 2.30

• RM275

Tags

NGSS.HS-PS3-1

An electric heater is rated 230V, 10 A. Calculate the power of the electric heater in kW.

• 2300

• 23

• 2.3

• 0.23

What is the unit of current?

• ohm

• ampere

• volt

• joule

Electrical power can be calculated using

• Resistance x Voltage
• Voltage x Current 
• Voltage ÷ Current