PHYSICAL SCIENCE REVIEW

Gabriel and Marley are studying sunspot activity for their science project. According to the graph they found, what year had the greatest number of sunspots?

• 1948

• 1958

• 1965

• 1980

Answer explanation

The graph indicates that 1958 had the highest recorded number of sunspots compared to the other years listed. This makes 1958 the correct answer.

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Lilah and Kennedy are playing with two magnets. What happens to the magnetic force between the magnets as they move them closer together?

• It remains constant.

• It decreases.

• It increases.

• It decreases then increases

Answer explanation

As Lilah and Kennedy move the magnets closer together, the magnetic force increases due to the stronger interaction between the magnetic fields. This is a fundamental property of magnets.

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During a science experiment, Marlee and Kennedy are observing the behavior of electric current in a circuit. Which describes the direction of the electric current in AC?

• It is constant.

• It is direct.

• It varies regularly.

• It varies irregularly.

Answer explanation

In an AC (alternating current) circuit, the direction of the electric current changes periodically, which means it varies regularly. This is different from direct current (DC), where the current flows in a constant direction.

During a science project, Marley and Kennedy are building a simple generator. Which component do they not need to include?

• wire coil

• magnet

• turbine

• battery

Answer explanation

In building a simple generator, Marley and Kennedy need a wire coil and a magnet to create electromagnetic induction. A turbine is not essential for a basic generator, and a battery is not needed as it is a power source, not a generator component.

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Blair and Marley are experimenting with magnets. They place a compass at different points around a bar magnet. Where is the magnetic field strongest?

• point A

• point B

• point C

• point D

Answer explanation

The magnetic field is strongest at point A, which is near the poles of the bar magnet. This is where the compass needle will align most strongly with the magnetic field lines, indicating the highest magnetic force.

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Kennedy is learning about electrical circuits in her science class. She wants to understand how voltage, current, and resistance are related. Which equation correctly expresses this relationship?

• V = I / R

• V = IR

• V = R / I

• V = I + R

Answer explanation

The correct equation that relates voltage (V), current (I), and resistance (R) is V = IR. This means voltage is the product of current and resistance, which is fundamental in understanding electrical circuits.

Lilah and Marley are working on a science project about electricity. They need to find out how electrical power is related to voltage and current. Which formula should they use?

• P = I + V

• P = IV

• P = I / V

• P = V / I

Answer explanation

The correct formula for electrical power is P = IV, where P is power, I is current, and V is voltage. This formula shows that power is the product of current and voltage, which is fundamental in understanding electricity.

Gabriel is setting up a simple electric circuit for a school project. In which type of circuit does the charge have only one loop to flow through?

• parallel

• series

• open

• uniform

Answer explanation

In a series circuit, the charge flows through a single path, meaning there is only one loop for the current to travel. This is in contrast to a parallel circuit, which has multiple paths.

Blair and Emma are setting up a holiday light display in their yard. They want to ensure that if one light goes out, the others stay lit. Which type of circuit should they use to achieve this?

• parallel

• series

• open

• uniform

Answer explanation

Blair and Emma should use a parallel circuit. In a parallel circuit, if one light goes out, the others remain lit because each light has its own path for electricity. This ensures the display stays illuminated even if one light fails.

Grant and Marley are working on a school project about home safety. They learn that the purpose of fuses and circuit breakers is to

• prevent circuits from overheating

• prevent breaks in the circuit

• allow circuits to be overloaded

• decrease the resistance

Answer explanation

Fuses and circuit breakers are safety devices designed to prevent circuits from overheating by interrupting the flow of electricity when it exceeds safe levels, thus protecting wiring and appliances from damage.