Electricity Review

Calculate the energy released from a battery in a hand vacuum cleaner that was switched on for 45 s. The voltage drop was 6 V and the current was 0.30 A.

• 35 J

• 81 J

• 42 J

• 82 W

Calculate the power rating of an electric toaster that uses 210 000 J while toasting bread for 140 s

• 1500 J

• 1200 W

• 1500 W

• 1300 J

Calculate the percent efficiency of an electric motor that uses 15 000 J of energy to produce

11 500 J of useful movement.

• 76.6%

• 82.3%

• 75.4%

• 23.3%

Calculate the cost of operating a heater of 1.75kw for 20 hours at rate of $0.13 per kwh?

• $6.75

• $4.55

• $53.43

• $45.53

How do you calculate voltage?

• Current X Resistance
• Resistance ÷ Current
• Current ÷ Resistance
• Measure it with a ruler

How do you calculate resistance?

• Voltage X Current
• Current ÷ Voltage
• Voltage ÷ Current
• Current X Amps

What voltage is needed to cause a 2A current flow through a 10Ω resistor?

• 5V
• 0.2V
• 20V
• 200V

What resistance is needed to cause a 50A current flow because of a 500V battery?

• 10Ώ
• 5Ώ
• 2500Ώ
• 550Ώ

If the battery produced 12.6 Volts and what would be the current flow be for a 6 Ohm resistor

• 2.1 Amps
• 2.4 Amps
• 1.71 Amps
• 15 Amps

With the engine running the charging system produces 14.5 Volts what would the current flow be if a resistance of 6 Ohms was present

• 2.41 Ohms
• 2.52 Ohms
• 2.1 Ohms
• 0.3333 Ohms