Electrical power and energy

If V is the potential difference, I is the current and R is the resistance, what is the formula for the electrical Power produced, P, in terms of V and I?

• P = V I

• P = V² I

Given a TV of operating voltage 240 V, operating current 1 A, what is its operating resistance R and power P? (Hint: use P = V x I and R = V / I)

• .004 Ω,

  240

• .004Ω,

  .004 W

• 240 Ω,

  240 W

• 240 Ω,

  .004 W

An iron of 750 W power is switched on for 30 mins. The energy consumed in kWH is ____ kWh

• 22500

• 375

• 22.5

• .375

An aircon of 1500 W power is switched on for 8 h. The energy consumed in kWH is ____ and the cost of usage is ____.

(Take cost of electricity to be 25 cents per kWh)

• 12000 kWh,

  $ 3000

• 12000kWh, $48000

• 12 kWh,

  $ 3

• 12kWh,

  $48

A kettle of power 2000 W is switched on for 25 mins. What is its energy consumed in kWh?

• 50000 kWh

• 50kWh

• 500 kWh

• .5kWh

• .83 kWh

How much time did you play video games if the PS4 uses 210 W of power and you used a total of 14.5 kWh of energy?

• 6.63 hrs

• 0.15 hrs

• 69 hrs

• 50 hrs

What is the power rating of an oven that uses 6 kWh of energy in 2 hours?

• 0.5 kW

• 8 kW

• 6 kW

• 3 kW

What is the electrical energy of a 80 W TV that is used for 120 hr

• 0.63 kWh

• 7700 kWh

• 1.57 kWh

• 9.6 kWh

The voltage supplied to a circuit is 18 V and the current running through is 20 A. What is the power generated?

• 3600 W

• .9 A

• 1.7 V

• 1.7 W

Arjun is using a device in his science project that operates at a voltage of 120 V and a current of 5 A. Samuel and Lily are curious to know how much power this device consumes. Can you help them calculate?

• 600 W

• 150 W

• 450 W

• 300 W