Electric Circuits

What is the mathematical expression for Ohm's Law?

• V = I + R

• V = I * R

• V = I ^ R

• V = I / R

State Kirchhoff's first law and its significance in electric circuits.

• The total current entering a junction is equal to the total current leaving the junction.

• The total power entering a junction is equal to the total power leaving the junction.

• The total resistance entering a junction is equal to the total resistance leaving the junction.

• The total voltage entering a junction is equal to the total voltage leaving the junction.

Explain the concept of time constant in RC circuits.

• The time constant in RC circuits is the time it takes for the voltage across the capacitor to reach approximately 50% of its final value when it is charging or discharging.

• The time constant in RC circuits is the time it takes for the voltage across the capacitor to reach approximately 63.2% of its final value when it is charging or discharging.

• The time constant in RC circuits is the time it takes for the voltage across the capacitor to reach approximately 80% of its final value when it is charging or discharging.

• The time constant in RC circuits is the time it takes for the voltage across the capacitor to reach approximately 30% of its final value when it is charging or discharging.

Calculate the power dissipated in a circuit with a resistance of 10 ohms and a current of 2A.

• 15W

• 40W

• 20W

• 5W

If a 12V battery is connected to a 4 ohm resistor, what is the current flowing through the circuit?

• 6A

• 10A

• 3A

• 2A

How does the resistance of a conductor affect the current flowing through it according to Ohm's Law?

• The current flowing through the conductor remains constant regardless of the resistance.

• The resistance of the conductor has no effect on the current flowing through it.

• The current flowing through the conductor decreases as the resistance increases.

• The current flowing through the conductor increases as the resistance increases.

In a series circuit with three resistors of 2 ohms, 4 ohms, and 6 ohms, what is the total resistance?

• 12 ohms

• 14 ohms

• 8 ohms

• 10 ohms

What is the condition for a capacitor to be fully charged in an RC circuit?

• When the capacitor reaches 50% of its maximum charge after 2 time constants.

• When the capacitor reaches 75% of its maximum charge after 3 time constants.

• When the capacitor reaches 85% of its maximum charge after 4 time constants.

• When the capacitor reaches approximately 99.3% of its maximum charge after 5 time constants.

Explain the concept of electrical power and its unit of measurement.

• Amps (A)

• Ohms (Ω)

• Volts (V)

• Watts (W)

If a 20 ohm resistor is connected to a 24V battery, what is the power dissipated in the circuit?

• 10.8W

• 15.2W

• 32.6W

• 28.8W