Q1. In an RC circuit, what is the time constant if R = 4 kΩ and C = 10 µF?
Solution:
Time constant τ = R * C = 4000 Ω * 10 x 10^-6 F = 40 ms.
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Q2. In a circuit with a 24V power supply and two resistors of 8Ω and 4Ω in series, what is the voltage drop across the 4Ω resistor?
Solution:
Total resistance R = 8Ω + 4Ω = 12Ω. Current I = V/R = 24V / 12Ω = 2A. Voltage drop V_R = I * R = 2A * 4Ω = 8 V.
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Q3. In a series RC circuit, what is the time constant (τ) defined as?
Solution:
The time constant τ in a series RC circuit is defined as τ = R * C, where R is resistance and C is capacitance.
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Q4. What is the current through a 10 Ω resistor if the voltage across it is 30 V?
Solution:
Using Ohm's Law: I = V/R = 30 V / 10 Ω = 3 A.
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Q5. In an RC circuit, what happens to the current as time approaches infinity after the switch is closed?
Solution:
As time approaches infinity, the capacitor becomes fully charged and the current approaches the maximum value V/R, where V is the voltage and R is the resistance.
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Q6. If the voltage across a resistor is doubled while the resistance remains constant, what happens to the current?
Solution:
According to Ohm's Law, if voltage is doubled and resistance is constant, current will also double.
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Q7. If a resistor of 10 ohms and a capacitor of 100 microfarads are in series, what is the time constant of the circuit?
Solution:
The time constant τ = R * C = 10 ohms * 100 x 10^-6 F = 0.001 seconds or 1 millisecond.
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Q8. If a circuit has a total resistance of 10 Ω and a current of 2 A, what is the voltage across the circuit?
Solution:
Using Ohm's Law: V = I * R = 2 A * 10 Ω = 20 V.
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Q9. A circuit has a total voltage of 12V and a total resistance of 3 ohms. What is the total current in the circuit?
Solution:
Using Ohm's Law, I = V/R. Here, I = 12V / 3Ω = 4 A.
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Q10. What is the formula for the energy stored in a capacitor?
Solution:
The energy (U) stored in a capacitor is given by U = 1/2 C V^2.
