Unit 4 Section 2: Electric Current Practice Scrimmage

What is the unit of electric current?

• Volt

• Ampere

• Ohm

• Watt

Answer explanation

The unit of electric current is the Ampere, often abbreviated as 'A'. It measures the flow of electric charge. Volt measures electric potential, Ohm measures resistance, and Watt measures power.

Which device is used to measure electric current in a circuit?

• Voltmeter

• Ammeter

• Resistor

• Battery

Answer explanation

An ammeter is specifically designed to measure electric current in a circuit, while a voltmeter measures voltage, a resistor limits current, and a battery provides power.

What is the symbol for electric potential difference (voltage)?

• I

• R

• V

• P

Answer explanation

The symbol for electric potential difference, commonly known as voltage, is represented by 'V'. This is a standard notation in physics and electrical engineering, distinguishing it from current (I) and resistance (R).

Tags

NGSS.HS-PS2-4

Which of the following is the correct formula for Ohm's Law?

• V = IR

• P = IV

• R = P/I

• I = P/V

Answer explanation

Ohm's Law states that voltage (V) is equal to the current (I) multiplied by the resistance (R). Therefore, the correct formula is V = IR, which shows the relationship between these three electrical quantities.

What is the unit of resistance?

• Ampere

• Volt

• Ohm

• Watt

Answer explanation

The unit of resistance is the Ohm, which measures how much a material opposes the flow of electric current. Ampere measures current, Volt measures voltage, and Watt measures power, making Ohm the correct choice.

Which component provides energy to a circuit?

• Resistor

• Battery

• Switch

• Ammeter

Answer explanation

The battery is the component that provides energy to a circuit, supplying the necessary voltage to drive current through the circuit. Resistors, switches, and ammeters do not generate energy.

What is the unit of electric power?

• Ohm

• Watt

• Volt

• Ampere

Answer explanation

The unit of electric power is the Watt. It measures the rate at which electrical energy is transferred. Ohm is for resistance, Volt for electric potential, and Ampere for current, making Watt the correct choice.

In a series circuit, how does the current through each resistor compare?

• It is different in each resistor

• It is the same in all resistors

• It depends on the voltage

• It is zero

Answer explanation

In a series circuit, the same current flows through all components. Therefore, the current through each resistor is the same, making the correct answer "It is the same in all resistors."

Which of the following is a symbol for a resistor in a circuit diagram?

• 
• 
• 
• 

What happens to the total resistance when resistors are added in parallel?

• It increases

• It decreases

• It stays the same

• It becomes zero

Answer explanation

When resistors are added in parallel, the total resistance decreases. This is because the total current increases, allowing more pathways for the current to flow, which reduces the overall resistance.