Yr10 Physics Electrical Energy & Power DCSG

To calculate the power of a 12V, 2A bulb when operating normally;

• P = I x V

• E = I x V x t

• P = E / t

• E = Q x V

• P = I² x R

To calculate the power of a motor with a resistance of 100 Ω and using a current of 0.5 A;

• P = I x V

• E = I x V x t

• P = E / t

• E = Q x V

• P = I² x R

A light bulb and ammeter are connected in series along with a switch and a 12V cell. The current measured by the ammeter is 1mA. Calculate the power dissipated by the bulb.

• P = I x V

• E = I x V x t

• P = E / t

• E = Q x V

• P = I² x R

A kettle has a power rating of 2.4kW and is powered by plugging into a mains power socket of 230V. To calculate the current going through the kettle;

• I = P / V

• I = E x V x t

• P = E / t

• E = Q x V

• I = √(P / R)

An iPad is an electrical device that is powered by a 5V, 2A battery. The manufacturer states that it can last up to 10 hours of continual video playback. To calculate the total amount of energy transferred in this time;

• P = I x V

• E = I x V x t

• E = P / t

• E = P x V

• P = I² x R

It requires 600 joules of energy to transfer a quantity of charge between points C and D of a circuit, which have a potential difference (voltage) of 30 volts. How much charge is transferred?

• Q = E x V

• Q = V / E

• P = E / t

• Q = E / V

• P = I² x R

What will be the current drawn by an electric bulb of 1000 W when it is connected to a source of 220 V?
Remember: I = P/V

• 4.55 A
• 28800 J or 28.8 KJ
• 80 W
• 200 W

The voltage supplied to a circuit is 17 V and the current running through is 10 A. What is the power generated?

• 170 W
• 170 A
• 1.7 V
• 1.7 W

Watts is the same as...

• Joules per second
• Voltage per second
• Current per second

A bulb of 100 W means that it will consume electrical energy at the rate of:

• 100 kJ per second.
• 100 kJ per hour.
• 100 joules per second.
• 100 joules per hour.