Principles of Electricity: 8th Grade Quiz Questions

Explain how a battery converts energy.

• A battery converts chemical energy into electrical energy.

• A battery converts electrical energy into chemical energy.

• A battery converts mechanical energy into electrical energy.

• A battery converts thermal energy into chemical energy.

Electrons flow from the negative to the positive terminal in a battery because:

• Electrons are negatively charged and are attracted to the positive terminal.

• Electrons are positively charged and are attracted to the negative terminal.

• Electrons are neutral and move randomly.

• Electrons are positively charged and are repelled by the positive terminal.

How does increasing resistance affect current in a circuit?

• A: Increasing resistance decreases the current in a circuit.

• B: Increasing resistance increases the current in a circuit.

• C: Increasing resistance has no effect on the current in a circuit.

• D: Increasing resistance doubles the current in a circuit.

Conductors have low resistance and allow easy electron flow, while insulators have high resistance and impede electron flow. Which of the following statements is true?

• Conductors have high resistance and impede electron flow.

• Insulators have low resistance and allow easy electron flow.

• Conductors have low resistance and allow easy electron flow.

• Insulators have low resistance and impede electron flow.

Ohm's Law describes the relationship between voltage, current, and resistance. Which formula represents this law?

• V = I * R

• I = V / R

• R = V / I

• All of the above

How would doubling the voltage in a circuit affect the current if resistance remains constant?

• The current would double.

• The current would remain the same.

• The current would be halved.

• The current would decrease slightly.

Explain why power plants use high voltage for long-distance electricity transmission.

• To increase the speed of electricity transmission

• To reduce power loss during long-distance transmission

• To decrease the cost of electricity production

• To improve the safety of electricity transmission

Compare AC and DC in terms of their direction of flow.

• A: DC flows in one constant direction, while AC periodically changes direction.

• B: AC flows in one constant direction, while DC periodically changes direction.

• C: Both AC and DC flow in one constant direction.

• D: Both AC and DC periodically change direction.

Why is AC preferred for home electricity supply?

• AC is more efficient for long-distance transmission.

• AC is safer than DC.

• AC is cheaper to produce.

• AC appliances are more durable.

Describe two ways that electrical power can be calculated.

• By multiplying voltage and current (P = V × I)

• By squaring current and multiplying by resistance (P = I²R)

• By adding voltage and resistance

• By dividing voltage by current