Ohms Law

What is the unit of electric current?

• Ohm (Ω)

• Volt (V)

• Watt (W)

• Ampere (A)

Answer explanation

The unit of electric current is Ampere (A).

What is the symbol for electric current?

• V

• R

• I

• E

Answer explanation

The symbol for electric current is I. It represents the flow of electric charge in a circuit.

What is the unit of resistance?

• Ampere (A)

• Watt (W)

• Ohm (Ω)

• Volt (V)

Answer explanation

The unit of resistance is Ohm (Ω).

What is the symbol for resistance?

• I

• V

• R

• E

Answer explanation

The symbol for resistance is 'R'. It represents the opposition to the flow of electric current in a circuit.

What is the force which causes electrical current to flow called?

• Current

• Voltage

• Resistance

• Electromotive force

Answer explanation

The force that causes electrical current to flow is called electromotive force (EMF).

According to Ohm's law, what is the relationship between current, voltage, and resistance?

• Exponential relationship

• No relationship

• Inversely proportional

• Directly proportional

Answer explanation

According to Ohm's law, current and voltage are directly proportional to each other when resistance is constant.

An emf of 10 volts is applied to a resistance of 20Ω. Calculate the current that will flow.

• 5 A

• 0.5 A

• 1 A

• 2 A

Answer explanation

The current flowing through a resistance is equal to the applied voltage divided by the resistance. In this case, the current is 10 volts divided by 20Ω, which equals 0.5 A. Therefore, the correct answer is 0.5 A.

When an emf of 50 volts is applied to a circuit, a current of 5 amperes flows. Calculate the resistance of the circuit.

• 5Ω

• 10Ω

• 15Ω

• 20Ω

Answer explanation

The resistance of the circuit can be calculated using Ohm's law: resistance = voltage / current. In this case, the resistance is 50 volts / 5 amperes = 10Ω. Therefore, the correct choice is 10Ω.

What is the total resistance of the circuit if R1 = 2Ω, R2 = 5Ω, R3 = 8Ω, and R4 = 3Ω, connected in series?

• 18Ω

• 20Ω

• 10Ω

• 15Ω

Answer explanation

The total resistance of series resistors, is calculated by adding all the resistances together. In this case, R1 + R2 + R3 + R4 = 2Ω + 5Ω + 8Ω + 3Ω = 18Ω. Therefore, the correct answer is 18Ω.

What potential is produced across a resistance of 23Ω if a current of 10 amps is flowing through it?

• 50 V

• 40 V

• 30 V

• 20 V