Calculate Electrical Energy and Power

A lamp changes __________ energy into light energy.

• Kinetic
• Electrical
• Sound
• Chemical

Tags

NGSS.HS-PS3-3

What is the unit of electrical power?

• watt, W

• volt, V

• ampere, A

• ohm, Ω

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.

Tags

NGSS.HS-PS3-2

If a device consumes 1500 Joules of energy in 10 seconds, what is it's power?

• 150 W

• 1500 W

• 15 W

• 1.5 W

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
• 5.22A

• 3.14 A

• 0.01 A

A current of 4 A flows through a 20 V car headlight bulb. Calculate the electric power.
 
Remember: I=P/V

• 80 W
• 200 W
• 2.5 W

• 4.55 W

Calculate the electric power of an electrical appliance of 20 V having a resistance of 10 ohms.
 
Remember: I=V/R and P=VI

• 200 W
• 40 W
• 2.5 W

• 79.20 kW

a pair of 15-watt computer speakers are connected in parallel to a 12-volt power supply. what is the electric current running through the speakers? 

• 1.25 A
• 0.8 A
• 12.5 A
• 180 A

How much power is dissipated in the resistor when the switch is closed?

• 0.8 W
• 1.2 W
• 7.2 W
• 30.0 W

Tags

NGSS.HS-PS3-1

Which of the graphs represents the equation, P = I²R, where P is power, I is current, and R is a constant?

• A
• B
• C
• D