MCQOPTIONS
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MCQOPTIONS
This section includes 36 Mcqs, each offering curated multiple-choice questions to sharpen your Network Theory knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In a certain series resonant circuit Vc = 100 V, VL = 100 V and VR = 35 V. The source voltage is |
| A. | 100 V |
| B. | 135 V |
| C. | 65 V |
| D. | 35 V |
| Answer» E. | |
| 2. |
In the following circuit shown below, the switch is moved from position a to b at t = 0.The iL(t) for t > 0 is |
| A. | (4-6t)e4t A |
| B. | (3-6t)e-4t A |
| C. | (3-9t)e-5t A |
| D. | (3-8t)e-5t A |
| Answer» D. (3-8t)e-5t A | |
| 3. |
In the circuit, switch 'S' is in the closed position for a very long time. If the switch is opened at time t = 0, then iL (t) in amperes, for t ≥ 0 is |
| A. | 8 + 2e-10t |
| B. | 10 |
| C. | 10(1 - e-2t) |
| D. | 8 e-10t |
| Answer» B. 10 | |
| 4. |
In the given circuit the switch is closed at time t = 0. The time taken for the circuit current to reach steady-state value is |
| A. | 0.2 sec |
| B. | 5 sec |
| C. | 2 sec |
| D. | 0.5 sec |
| Answer» E. | |
| 5. |
In the circuit shown below, switch S1 and S2 are in open and close position respectively for long time. At t = t0, switch S1 is closed and switch S2 is opened. What would be the current through R1 immediately after the transition of switches? |
| A. | 0 mA |
| B. | 1 mA |
| C. | 0.5 mA |
| D. | 2 mA |
| Answer» C. 0.5 mA | |
| 6. |
A first order circuit is excited with a dc source. The current i(t) through any element of the circuit can be written as (if and ii are the final and initial values, respectively, of the current) |
| A. | \({i_i} - \left( {{i_i} - {i_f}} \right){e^{\frac{{ - t}}{T}}}\) |
| B. | \({i_f} - \left( {{i_f} - {i_i}} \right){e^{\frac{{ - t}}{T}}}\) |
| C. | \({i_i} - \left( {{i_f} - {i_i}} \right){e^{\frac{{ - t}}{T}}}\) |
| D. | \({i_f} - \left( {{i_i} - {i_f}} \right){e^{\frac{{ - t}}{T}}}\) |
| Answer» C. \({i_i} - \left( {{i_f} - {i_i}} \right){e^{\frac{{ - t}}{T}}}\) | |
| 7. |
In the circuit shown above, the switch is closed after a long time. The current iS (0+) through the switch is |
| A. | 1 A |
| B. | 2/3 A |
| C. | 1/3 A |
| D. | 0 A |
| Answer» D. 0 A | |
| 8. |
For the circuit diagram shown below, calculate the voltage across capacitor V(t) at t = 160 μs? |
| A. | 16.5 V |
| B. | 18.4 V |
| C. | 20.2 V |
| D. | None of the above |
| Answer» C. 20.2 V | |
| 9. |
In the circuit shown in the following figure, the switch is kept closed for a long time and then opened at t = 0. The value of current 'i', just before opening the switch (t = 0-) and after opening the switch (t = 0+) are, respectively. |
| A. | \(\frac{3}{4}A\;and\;1\;A\) |
| B. | \(\frac{7}{6}A\;and\frac{5}{2}A\) |
| C. | \(1\;A\;and\frac{7}{6}A\) |
| D. | 1 A and 1 A |
| Answer» D. 1 A and 1 A | |
| 10. |
A step voltage of 10 V applied to the circuit at t = 0. The current through the resistor R just after t = 0 and at steady state are: |
| A. | 100 mA, 50 mA |
| B. | 50 mA, 50 mA |
| C. | 100 mA, 100 mA |
| D. | 75 mA, 75 mA |
| Answer» B. 50 mA, 50 mA | |
| 11. |
A series RC circuit has a time constant of 0.1 sec and its value of C is 2 microFarads. The value of R is |
| A. | 0.05 MΩ |
| B. | 0.05 Ω |
| C. | 0.1 MΩ |
| D. | 0.01 Ω |
| Answer» B. 0.05 Ω | |
| 12. |
A switch is connected in between a 12 V battery and an uncharged capacitor and a 1 KΩ resistor. At the time instant when the switch is closed, the voltage across the capacitor is: |
| A. | 6 V |
| B. | 12 V |
| C. | 0 V |
| D. | 24 V |
| Answer» D. 24 V | |
| 13. |
Inductive load of resistance 20 Ω and inductance 0.1 H is connected in series and switched on to an AC voltage of V = 100 sin(200 t + α). Find the angle α such that there is no transients? |
| A. | 45° |
| B. | 60° |
| C. | 30° |
| D. | 75° |
| Answer» B. 60° | |
| 14. |
In a series RL circuit the value of inductance is 1 Henry and resistance is 10 ohms. What is the time constant of the circuit? |
| A. | 0.1 sec |
| B. | 1 sec |
| C. | 10 sec |
| D. | None of the above |
| Answer» B. 1 sec | |
| 15. |
A 10 V DC source is connected to a series combination of 5 ohm resistor and 0.1 μF capacitor. What will be the current through the circuit under steady state ? |
| A. | 2 A |
| B. | 10 A |
| C. | 1 A |
| D. | 0 A |
| Answer» E. | |
| 16. |
A series R-L circuit (R = 4 Ω and L = 0.01 H) is excited by a voltage (in volt) v(t) = 283 sin (300t + 90°). The current in the circuit will be |
| A. | 40 sin ( 300t + 53.1°) A |
| B. | 40 sin ( 53.1°) A |
| C. | 40√2 sin ( 300t + 53.1°) A |
| D. | 40√2 sin ( 53.1°) A |
| Answer» D. 40√2 sin ( 53.1°) A | |
| 17. |
By the decomposition property of linear system, we can separate our 2 components of the linear system namely: |
| A. | Zero input component, zero state component |
| B. | Steady state component, transient component |
| C. | Linear component, non-linear component |
| D. | Line and a Circle |
| Answer» B. Steady state component, transient component | |
| 18. |
In a loss-free R-L-C circuit the transient current will be: |
| A. | Oscillating |
| B. | Non-oscillating |
| C. | Sinusoidal wave |
| D. | Square wave |
| Answer» D. Square wave | |
| 19. |
In the circuit shown, the switch is opened at t = 0. The circuit is |
| A. | Critically damped |
| B. | Under-damped |
| C. | Over-damped |
| D. | Undamped |
| Answer» D. Undamped | |
| 20. |
In the circuit shown, the switch SW is thrown from position A to position B at time t = 0. The energy (in μJ) taken from the 3V source to charge the 0.1μF capacitor from 0V to 3V is |
| A. | 0.3 |
| B. | 0.45 |
| C. | 0.9 |
| D. | 3 |
| Answer» D. 3 | |
| 21. |
An AC source is connected to an RL series circuit. The phase of the source current, θ, with respect to the source voltage will be: |
| A. | 90° lead |
| B. | -90° < θ < 0° |
| C. | 90° lag |
| D. | 0° < θ < 90° |
| Answer» C. 90° lag | |
| 22. |
In the network shown below, switch is opened at t = 0 after long time. The current iL(t) for t > 0 is given as |
| A. | \({e^{ - 2t}}\left( {2\cos t + 4\sin t} \right)A\) |
| B. | \({e^{ - 2t}}\left( {3\sin t - 4\cos t} \right)A\) |
| C. | \({e^{ - 2t}}\left( {-4\sin t + 2\cos t} \right)A\) |
| D. | \({e^{ - 2t}}\left( {2\sin t - 4\cos t} \right)A\) |
| Answer» E. | |
| 23. |
Calculate the time constant for the RC circuit shown here. |
| A. | 25 ms |
| B. | 20 ms |
| C. | 12 ms |
| D. | 50 ms |
| Answer» D. 50 ms | |
| 24. |
A series RL circuit having a resistance of 20 Ω and inductance of 8 H is connected to a DC voltage source of 120 V at t = 0. The current in the circuit at t = 0.6 sec is |
| A. | 0 A |
| B. | 2.33 A |
| C. | 4.66 A |
| D. | 1 A |
| Answer» D. 1 A | |
| 25. |
In the figure shown, the capacitor is initially uncharged. Which one of the following expressions describes the current I(t) (in mA) for |
| A. | \(I\left( t \right) = \frac{5}{3}\left( {1 - {e^{ - \frac{t}{\tau }}}} \right),\tau = \frac{2}{3}\;msec\) |
| B. | \(I\left( t \right) = \frac{5}{2}\left( {{e^{ - \frac{t}{\tau }}}} \right),\tau = \frac{2}{3}\;msec\) |
| C. | \(I\left( t \right) = \frac{5}{3}\left( {1 - {e^{ - \frac{t}{\tau }}}} \right),\tau = 3\;msec\) |
| D. | \(I\left( t \right) = \frac{5}{2}\left( {1 - {e^{ - \frac{t}{\tau }}}} \right),\;\tau = 3\;msec\) |
| Answer» B. \(I\left( t \right) = \frac{5}{2}\left( {{e^{ - \frac{t}{\tau }}}} \right),\tau = \frac{2}{3}\;msec\) | |
| 26. |
Consider the following statements:i. Power factor will be unity.ii. Current in circuit will be maximum.iii. Current in circuit will be minimum.Which of these statements are correct with respect to resonance in R-L-C parallel circuit? |
| A. | i, ii and iii |
| B. | i and ii only |
| C. | ii and iii only |
| D. | i and iii only |
| Answer» E. | |
| 27. |
In the s-domain circuit analysis, the circuit natural response is contributed by |
| A. | System function poles only |
| B. | Forcing function poles only |
| C. | Both system and forcing function poles |
| D. | Both poles and zero of the system only |
| Answer» B. Forcing function poles only | |
| 28. |
Determine the inductor voltage ‘V’ in the circuit shown below for t > 0? |
| A. | 25 e-2t |
| B. | 2.5 e-0.5t |
| C. | -2.5 e-0.5t |
| D. | -25 e-2t |
| Answer» E. | |
| 29. |
In the circuit shown below, steady state was reached when the switch ‘s’ was open. The switch was closed at t = 0. Then initial value of the current through the capacitor 2C is? |
| A. | 0 A |
| B. | 1 A |
| C. | 2 A |
| D. | 3 A |
| Answer» D. 3 A | |
| 30. |
An inductor L , 5 Ω and 10 Ω resistors are all connected in series across a voltage source v(t) = 50 cos ωt volt. If the power consumed by the 5 Ω resistor is 10 W, then the power factor of the circuit is |
| A. | 0.3 |
| B. | 0.4 |
| C. | 0.6 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 31. |
In the circuit shown above, switch S is closed at t = 0. The time constant of the circuit and initial value of current i(t) are |
| A. | 30 sec, 0.5 A |
| B. | 60 sec, 1.0 A |
| C. | 20 sec, 1.0 A |
| D. | 20 sec, 0.5 A |
| Answer» D. 20 sec, 0.5 A | |
| 32. |
In the figure, initial voltage on C is V0S is closed at t = 0. The IL for t > 0 isWhere \(\omega _0^2 = 1/LC\) |
| A. | -ω0 CV0 sin ω0 t |
| B. | ω0 V0 sin ω0 t |
| C. | -ω0 V0 sin ω0 t |
| D. | ω0 CV0 sin ω0 t |
| Answer» E. | |
| 33. |
In a series RLC circuit at resonance, the magnitude of the voltage developed across the capacitor |
| A. | Is always zero |
| B. | Can never be greater than the input voltage |
| C. | Can be greater than the input voltage, however, is in 90° out of phase with the input voltage |
| D. | Can be greater than the input voltage, and is in phase with the input voltage |
| Answer» D. Can be greater than the input voltage, and is in phase with the input voltage | |
| 34. |
A voltage of 24 V DC is applied through switch S to an R – L series circuit. Switch S was initially open At time t = 0, switch is closed. The rate of change of current through the resistor is 8 A/s, while the current through the inductor is 8 A. If the value of the inductor is 1 H, then for this condition the value of the resistor will be |
| A. | 1 Ω |
| B. | 2 Ω |
| C. | 3 Ω |
| D. | 4 Ω |
| Answer» C. 3 Ω | |
| 35. |
An RLC series resonance boosts: |
| A. | current |
| B. | resistance |
| C. | frequency |
| D. | inductance |
| Answer» B. resistance | |
| 36. |
In the circuit shown in the figure, the switch S is closed at time t = 0. The supply current at t = 0+ and the capacitor voltage at t → ∞ are, respectively |
| A. | 0 and V |
| B. | \(\frac{V}{{{R_1}}}~and~\frac{{V{R_2}}}{{{R_1} + {R_2}}}\) |
| C. | \(\frac{V}{{{R_1} + {R_2}}}\;and\frac{{V{R_2}}}{{{R_1} + {R_2}}}\) |
| D. | VR1 and V |
| Answer» C. \(\frac{V}{{{R_1} + {R_2}}}\;and\frac{{V{R_2}}}{{{R_1} + {R_2}}}\) | |