Electricity Questions Chapter 3

Is it less expensive to operate the electric heating unit in Question 12 on 240 V or 120 V?

120V because 120V will make the current flow slower but still produce the same amount of current

An electric heating element has a resistance of 16 V and is connected to a voltage of 120. how much current will flow in this circuit?

120V/16V = 7.5A

If the voltage in Question 12 is reduced to 120 V, how much current would be needed to produce the same amount of power?

5,000W/120V = 41.67A, 41.67A/2 = 20.83A, 240V/2 = 120V, 5-kW/2 = 2.5-kW

A 5-kW electric heating unit is connected to a 240-V line. What is the current flow in the circuit?

5-kW x 1000 = 5000W, 5,000W/240V = 20.83 A

What is a coulomb?

A measure of charge

What is an ampere?

A measure of the amount of electricity that is flowing through a circuit

Define watt.

A measure of the amount of power that is being used in a circuit

Define voltage.

The potential difference between two points of a conducting wire carrying a constant current of 1 ampere when power dissipated between these points is 1 watt

Define ohm.

The unit of resistance to current flow