Electric Circuits Review

If Jenna is trying to complete the circuit in the picture, which item should she attach the alligator clips to in order to create a complete simple circuit?

• string

• paper

• piece of wood

• piece of foil

Sue could not figure out why her circuit would not work. Can you help her figure out the problem? Which part of the circuit is not complete?

• Point A

• Point B

• Point C

• Point D

Mary is preparing an experiment to test how well unknown materials conduct electricity. She will use two probes to touch each object. First, she wants to be sure the probes are working properly. Which of the following materials should Mary choose to test the probes?

• a copper penny

• a rubber ball

• a plastic bottle

• a piece of wood

Electrical wires have a plastic coating because ____.

• plastic is an insulator and will help to protect someone who touches the wire from getting shocked

• plastic is a good conductor, so the electricity will flow faster through the wire

• the plastic keeps the wires hot enough to conduct electricity

• the plastic cools the wires so that they do not melt when electricity flows through them

Which statement best defines an electrical circuit?

• a closed path of conduction in which electrons can flow

• a closed path of conduction in which protons can flow

• a closed path of conduction in which neutrons can flow

• a closed path of conduction in which leptons can flow

A teacher has 4 beakers labeled A through D. Each beaker holds 150 mL of water mixed with 5 g of a different substance. The substances are sugar, flour, salt, and sand. The teacher has built a circuit like the one in the diagram below. After plugging the adaptor into the wall socket, the teacher dips the probe on the end of the cable into each beaker. The bulb produces the brightest light when the cable is inserted in the beaker of saltwater. Which explanation supports the results of the experiment best?

• Saltwater is a better conductor than the other mixtures.

• Saltwater eats away the metal threads inside a light bulb.

• Salt dissolves more easily in water than sugar, flour, and sand do.

• Salt grains are the right size to conduct electricity well.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS2-3

Michelle got a shock from touching an electrical cord. What is the most likely problem with the cord?

• There is too much current.

• There is not enough current.

• The insulation is cracked.

• There is too much insulation.

Rafael has a circuit like the one shown in this diagram. Which of the following items should Rafael add to the circuit to make the light shine?

• A switch to the right of the light

• A power source such as a battery

• A second wire from the light to the switch

• A light to the left of the switch

Tags

NGSS.MS-ETS1-1

A clerk in a store hangs a string of colorful lights to attract customers to a display. He plugs in the lights and they burn brightly for several hours. Then, all of the new lights stop shining at once. The store’s other lights continue to shine. Which of the following could explain why this has happened?

• There is something wrong with the power supply to the building.

• The string forms a series circuit, and one or more lights are broken.

• The string forms a parallel circuit, and one or more lights are broken.

• The lights’ colors determine how long they burn.

Jane's circuit is not working. What rule about an electric current has she broken?

• A current is continuous.

• A current is not continuous.

• A current should not have many parts.

• A current should not have too much power.