Science Final Review

What happens when someone lets go of the button on an electric doorbell?

• The electromagnet gets stronger.

• The circuit is broken and the electromagnet turns off.

• The current moving through the circuit changes direction.

• The metal striker hits the bell.

A magnet placed against the wall of a metal shed falls to the ground, where it attracts a nail. What is the most likely explanation for this observation?

• The wall is the opposite pole from the magnet.

• The shed is not made of iron or steel.

• The magnet is not magnetized.

• The nail pulled the magnet to the ground.

Tags

NGSS.HS-PS3-5

A circuit contains two light bulbs connected in parallel. What would happen to the brightness of each light bulb if two more light bulbs were added in parallel to the first ones?

• The brightness of each bulb would decrease because the total resistance of the circuit would decrease.

• The brightness of each bulb would increase because the total resistance of the circuit would increase.

• The brightness of each bulb would remain the same even though the total resistance of the circuit would decrease.

• The brightness of each bulb would remain the same even though the total resistance of the circuit would increase.

A flashlight has a resistance of 2.4 Ohm . What voltage is applied by the batteries if the current in the circuit is 2.5 A? V = I x R

• 6.0 V

• 4.9 V

• 1.0 V

• 0.96 V

Briana builds a circuit that has a resistance of 8.0 Ohm . What voltage should she apply to have a current of 0.8 A? V = I x R

• 7.2 V

• 0.10 V

• 10 V

• 6.4 V

Which best describes a difference between electric current and static electricity?

• Static electricity involves the movement of electrons, and electric current involves the movement of protons.

• Electric current involves the movement of electrons, and static electricity involves the movement of protons.

• Static electricity is continuous, and electric current is not continuous.

• Electric current is continuous, and static electricity is not continuous.

A circuit is a path along which electric current flows. How would changing the battery in a circuit from 9 volts to 1.5 volts most likely affect the circuit?

• The resistance in the circuit would decrease.

• More electric charge would flow in the circuit.

• The resistance in the circuit would increase

• Less electric charge would flow in the circuit.

Which best compares AC and DC?

• AC is used only in generators, and DC is used only in motors.

• AC flows in one direction, and DC repeatedly switches direction.

• DC flows in one direction, and AC repeatedly switches direction.

• DC is used only in generators, and AC is used only in motors.

Two objects are held close together. When they are released, they move toward one another. Which conclusion is supported by this evidence?

• The objects have no charge.

• The objects have opposite charges.

• The objects are both positively charged.

• The objects are both negatively charged.

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

Which change will decrease the electric force between two positively charged objects?

• adding neutrons

• removing electrons

• moving them closer together

• moving them farther apart

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5