Physical Science Unit 4 Study Guide

Which describes the difference between the light bulbs in the series circuit and the light bulbs in the parallel circuit?

• All of the light bulbs are equally bright in both series circuits and parallel circuits

• In the parallel circuit all of the bulbs are equally bright and in the series circuit the brightness decreases as the current flows through each bulb

• In the series circuit all of the bulbs are equally bright and in the parallel circuit the brightness decreases as the current flows through each bulb.

• In series circuits the brightness of each bulb decreases as the current flows through each bulb and in parallel circuits the brightness of each bulb decreases as they are placed further from the battery

During an electricity investigation, a student stated, “When the voltage increases current increases.” Which equation can be used to justify this claim?

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If a circuit has a current of 0.25 A and a voltage of 3 V, how much resistance is in the circuit?

• 0.083 ohms

• 0.75 ohms

• . 1.5 ohms

• 12 ohms

Mary wants to investigate the relationship between magnetism and the movement of an electrical charge. She has a coil of wire hooked to an ammeter to measure current. She has a moveable magnet inside the coil. As she moves the magnet within the coil, the ammeter indicates a certain current. Mary wants to increase the amount of current from the device. Which action would be the BEST to increase the current and why?

• Use a differently shaped magnet, because it would increase the magnetic field.

• Increase the diameter of coil, because more of the magnetic field will be included

• Reduce the number of coils because this would increase the effect of the magnetic field.

• Move the magnet faster within the coil, because this will increase the rate of change of the magnetic field.

Caroline connected four light bulbs (P, Q, R, and S) in a circuit but did not tell her classmates the arrangement of the bulbs. She wanted them to figure out how current flows through the circuit. The table displays how the bulbs behave when each bulb is removed and then replaced.

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A flashlight bulb with a resistance of 20 ohms requires a potential difference of 6 volts across the terminals of the flashlight batteries in order to burn at a required brightness as shown. Flowing current that is higher than normal is referred to as overload.

• 0.3A

• . 3.33A

• 26A

• 120A

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• .34.50 volts

• 163 volts

• When the orientation of the magnet is reversed the current will change sign because the direction of the current changes as the orientation of the magnetic field changes.

• When the orientation of the magnet is reversed the current will remain the same because the direction of the current is not affected by the orientation of the magnetic field.

• When the north pole of the magnet enters either coil the current will be the same as the current produced by inserting the south pole of the magnet. This is because the current only depends on the presence of a magnetic field, not on the orientation of the field.

• When the north pole of the magnet enters either coil the current will be positive and when it exits the coils the current will be negative. This is because the current changes direction as the magnetic field changes.

Which of the following works BEST for household wiring?

• . A series circuit, with a circuit breaker for stopping the flow of current in an electric circuit as a safety measure.

• A parallel circuit, with a surge protector for stopping the flow of current in an electric circuit as a safety measure.

• A series circuit, with a surge protector for stopping the flow of current in an electric circuit as a safety measure.

• A parallel circuit, with a circuit breaker to stop the current flow in an electric circuit as a safety measure.

Mark learned about electrical circuits at school and wanted to build one at home. He used the circuit shown in the diagram. However, none of the lights were glowing. He discovered that the current did not flow due to a broken filament in one of the bulbs.

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