Unit 8 Test Review

What is the unit of electric charge?

• Volt

• Ohm

• Coulomb

• Ampere

Answer explanation

The unit of electric charge is the Coulomb, which quantifies the amount of charge. Volt measures electric potential, Ohm measures resistance, and Ampere measures current, making Coulomb the correct choice.

Which law explains the force between two charges?

• Ohm’s Law

• Newton’s Law

• Coulomb’s Law

• Gauss’s Law

Answer explanation

Coulomb’s Law describes the electrostatic force between two charges, stating that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

Tags

NGSS.HS-PS2-4

Which quantity is a vector?

• Charge

• Electric field

• Resistance

• Energy

Answer explanation

The electric field is a vector quantity, as it has both magnitude and direction. In contrast, charge, resistance, and energy are scalar quantities, which only have magnitude.

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

What is the force between two 1 C charges placed 1 meter apart?

• 9 × 10⁹ N

• 1 N

• 1.6 × 10^-19 N

• 0 N

Tags

NGSS.HS-PS2-4

Which of the following materials is an insulator?

• Copper

• Silver

• Glass

• Aluminum

Answer explanation

Glass is an insulator, meaning it does not conduct electricity well. In contrast, copper, silver, and aluminum are all good conductors of electricity.

Tags

NGSS.MS-PS3-3

If the distance between two charges is doubled, the force becomes:

• 4 times greater

• 2 times greater

• 8 times greater

• not enough information

Answer explanation

Tags

NGSS.HS-PS2-4

Electric field lines never:

• Cross

• Curve

• Start at positive charges

• End at negative charges

Answer explanation

Electric field lines never cross because crossing would imply that a single point in space has multiple electric field directions, which is not possible. They can curve, start at positive charges, and end at negative charges.

The SI unit of current is:

• Volt

• Ohm

• Ampere

• Coulomb

Answer explanation

The SI unit of current is the Ampere, which measures the flow of electric charge. Volt measures electric potential, Ohm measures resistance, and Coulomb measures electric charge.

What does Ohm’s Law state?

• V=IR

• V=I/R

• I=VR

• R=V+I

Answer explanation

Ohm's Law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, with resistance (R) as the constant of proportionality. Thus, the correct formula is V=IR.

A 2 A current flows through a 4 Ω resistor. What is the voltage?

• 2 V

• 4 V

• 6 V

• 8 V

Answer explanation

Using Ohm's Law (V = I × R), where I = 2 A and R = 4 Ω, the voltage V = 2 A × 4 Ω = 8 V. Therefore, the correct answer is 8 V.