Circuits, Motors, Generators, and Transformers

A wire carries a current of 2 A over a period of 30 seconds. What total charge moves through the wire in this time interval?

• 15 C

• 60 C

• 0.0666 C

• 120 C

If a string of light bulbs is wired in a parallel circuit, what happens to the brightness of the bulbs when another bulb is added to the string?

• The brightness remains the same.

• The bulbs get dimmer.

• The bulbs get brighter.

• None of the bulbs will work.

If a 250 V resistor conducts a current of 5 A, what is the voltage difference across its ends?

• 1250 V

• 0,02 V

• 50 V

• 12.5 V

A motor is a device that...

• converts electrical energy into mechanical energy.

• converts mechanical energy into kinetic energy.

• converts mechanical energy into electrical energy.

• converts electrical energy into kinetic energy.

A generator is a device that converts...

• mechanical energy into electrical energy.

• electrical energy into kinetic energy.

• mechanical energy into kinetic energy.

• electrical energy into mechanical energy.

A transformer has 5 turns on the secondary side and 25 turns on the primary side. If the primary voltage is 110 v what is the secondary voltage?

• 550 V

• 22 V

• 220 V

• 55 V

Which of the following does not affect the resistance of a wire to direct current?

• Temperature

• Length of the wire

• The shape of the wire

• Thickness

In a series circuit, what stays the same?

• Voltage

• Current

• Resistance

In a parallel circuit what stays the same?

• Current

• Voltage

• Resistance

Three resistors, 5 Ohms, 10 Ohms, and 15 Ohms are connected in parallel. Find the equivalent resistance.

• 30 Ohms

• 0.366 Ohms

• 27.2 Ohms

• 2.72 Ohms