Circuits

The picture shows a series circuit with three lit bulbs. How many of the bulbs will remain lit if the wire is cut at the point shown by the arrow? (5.6B)

• 0

• 1

• 2

• 3

Which of these changes to the electric circuit shown will cause the lightbulb to light up? (5.6B)

• Straightening the wire so that the current can flow more easily

• Adding a switch and more wire so that the current can flow more easily

• Turning one battery so that its positive end connects to the other battery's negative end

• Making the length of wire the same on both sides of the lightbulb

A string of light with small bubs is shown here. The bulbs are connected by wire that is covered with an insulator. When the lights are on, electricity travels in ----(5.6B)

• a complete circuit

• a sound wave

• a light ray

• an incomplete path

The diagram shows the metal posts that are usually found on a battery. The battery can be connected to a bell and a switch to produce sound. Which statement best explains why there are two metal posts on the battery? (5.6B)

• The battery needs only one metal post to connect to the bell, but the other metal post is present in case the first post fails to work.

• The battery needs to form a complete circuit that starts with one metal post and ends with the other metal post.

• One metal post makes a complete circuit with the switch, and the other metal post makes a complete circuit with the bell.

• One metal post makes the bell start to ring, and the other metal post makes the bell ring louder.

Most cars have lights, power locks, radios, and other equipment that use electricity. Electric circuits power this equipment. Each circuit has a fuse that completes it. The picture below shows one type of fuse a car may have. Which of these describes one thing that could happen if the wire in a car fuse burns out? (5.6B)

• The car's lights will burn brighter.

• The car's radio will not work.

• The car's turn signal will blink too slowly.

• The car's power windows will open faster.

A group of students built the circuit shown here. The lightbulb does not glow. Which statement explains this observation? (5.6B)

• The battery is not charged.

• The lightbulb is not part of a complete circuit.

• The circuit does not have a switch.

• The bell uses most of the energy from the battery.

A simplified diagram of a system using solar energy is shown. To recharge the battery for later use without lighting the bulb, which of the following switches should be closed? (5.6B)

• Switch S only

• Switches R and S only

• Switches R and T only

• Switches R, S, and T

All the lightbulbs in this circuit are lit. Which change would cause all the bulbs to go out? (5.6B)

• Removing Wire 1

• Removing Wires 2 and 4

• Removing Wires 2 and 5

• Removing Wires 3 and 4

Students constructed a circuit using different-colored lightbulbs. What will happen if Switch 3 is closed and the other switches are left open? (5.6B)

• Only the white bulb will operate.

• None of the bulbs will operate.

• Only the white and yellow bulbs will operate.

• Only the red and blue bulbs will operate.

This circuit has three lightbulbs and a bell. Which procedure will result in only the blue lightbulbs operating? (5.6B)

• Close Switches 1 and 2 and leave Switch 3 open

• Close Switch 3 and leave Switches 1 and 2 open

• Close Switches 2 and 3 and leave Switch 1 open

• Close Switch 2 and leave Switches 1 and 3 open