MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 1800 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics & Communication Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1651. |
A n-port network is said to be active if power in the ckt is __________ . |
| A. | P > 0 |
| B. | P < 0 |
| C. | P = 0 |
| D. | P = ‚àû |
| Answer» C. P = 0 | |
| 1652. |
In a purely capacitive circuit, the current __________ the voltage by __________ . |
| A. | lags, 0° |
| B. | leads, 90° |
| C. | lags, 90° |
| D. | lags, 45° |
| Answer» C. lags, 90¬∞ | |
| 1653. |
If Ia, Ib, Ic are line currents and Ia0 is the zero sequences component of Ia then |
| A. | Ia0 = Ia |
| B. | Ia0 = Ia + Ib + Ic |
| Answer» B. Ia0 = Ia + Ib + Ic | |
| 1654. |
The driving point impedance of a network is The number of energy storing elements in the network is |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» C. 3 | |
| 1655. |
Eddy current loss is proportional to |
| A. | f and B2m |
| B. | f2 and B2m |
| C. | f2 and Bm |
| D. | f and Bm |
| Answer» C. f2 and Bm | |
| 1656. |
A 0.5 μF capacitor is connected across a 10 V battery. After a long time, the circuit current and voltage across capacitor will be |
| A. | 0.5 A and 0 V |
| B. | 0 A and 10 V |
| C. | 20 A and 5 V |
| D. | 0.05 A and 5 V |
| Answer» C. 20 A and 5 V | |
| 1657. |
For a full rectified sine wave, the form factor and peak factor respectively are |
| A. | 1.57 and 2 |
| B. | 1.57 and 2 |
| C. | 1.11 and 1.11 |
| D. | 1.11 and 2 |
| Answer» D. 1.11 and 2 | |
| 1658. |
The function Z(s) has a pole at infinity if |
| A. | the degree of numerator and denominator of Z(s) are equal |
| B. | the numerator of Z(s) is one degree higher than denominator |
| C. | the denominator of Z(s) is one degree higher than numerator |
| D. | the degree of numerator and denominator are either equal or differ by one |
| Answer» C. the denominator of Z(s) is one degree higher than numerator | |
| 1659. |
Two capacitors of 2 μF and 4 μF capacitance are connected in series across a 30 V dc battery. After the capacitors have been charged, the voltage across them will be |
| A. | 15 V each |
| B. | 10 V and 20 V |
| C. | 20 V and 10 V |
| D. | 30 V each |
| Answer» D. 30 V each | |
| 1660. |
A capacitor having capacitance C is raised to voltage V. The energy stored will be |
| A. | CV2 |
| B. | V2/C |
| C. | 0.5 V2C |
| D. | 0.5 C2V |
| Answer» D. 0.5 C2V | |
| 1661. |
To neglect a current source the terminals across the source are |
| A. | replaced by some resistance |
| B. | replaced by capacitance |
| C. | open-circuited |
| D. | short-circuited |
| Answer» D. short-circuited | |
| 1662. |
, i(t) = |
| A. | 3e-4t - e-5t |
| B. | 3e-4t - 2e-3t |
| C. | 2e-4t - 5e-2t |
| D. | 3e-4t - e-t |
| Answer» C. 2e-4t - 5e-2t | |
| 1663. |
Complex poles give rise to oscillatory terms in the response. |
| A. | 1 |
| B. | |
| C. | voltage |
| D. | current |
| Answer» B. | |
| 1664. |
In an underdamped RLC series circuit, the natural frequency is ωn. The frequency of damped oscillations is |
| A. | ωn |
| B. | less than ωn |
| C. | more than ωn |
| D. | 2 ωn |
| Answer» C. more than œân | |
| 1665. |
For a series resonant circuit at low frequency impedance is __________ and at high frequency circuit impedance is __________ . |
| A. | capacitive, inductive |
| B. | inductive, capacitive |
| C. | resistive, inductive |
| D. | capacitive, resistive |
| Answer» B. inductive, capacitive | |
| 1666. |
Thevenin's impedance of an ac network is in general |
| A. | resistance |
| B. | R and L in series |
| C. | R and C in series |
| D. | Either R and L or R and C in series |
| Answer» E. | |
| 1667. |
If operator 'a' = 1 ∠120° then (1 + a) = |
| A. | #NAME? |
| B. | #VALUE! |
| C. | a |
| D. | -1 |
| Answer» C. a | |
| 1668. |
Figure shows the variation of Z(ω) for a positive real function. The function is |
| A. | RC impedance |
| B. | RL impedance |
| C. | RLC impedance |
| D. | Reactance function |
| Answer» B. RL impedance | |
| 1669. |
Transient current in a loss free LC circuit when excited from an ac source is an __________ sine wave. |
| A. | undamped |
| B. | over damped |
| C. | under damped |
| D. | critically damped |
| Answer» D. critically damped | |
| 1670. |
In figure, the power associated with 3 A source is |
| A. | 36 W |
| B. | 24 W |
| C. | 16 W |
| D. | 8 W |
| Answer» C. 16 W | |
| 1671. |
In figure, the switch is initially open. At t = 0 switch is closed. vc (0+) and iL (0+) are |
| A. | 60 V and - 0.3 A |
| B. | 150 V and zero |
| C. | zero and 0.3 A |
| D. | 90 V and - 0.3 A |
| Answer» B. 150 V and zero | |
| 1672. |
A series RL circuit is switched on to an exponential source Ve-at at t = 0. The current |
| A. | 1 |
| B. | |
| C. | incidence of branches to nodes |
| D. | incidence of branches to loops |
| Answer» C. incidence of branches to nodes | |
| 1673. |
If VA = - 10 V and VB = - 15 V, VAB = 5 V. |
| A. | 1 |
| B. | |
| C. | Both A and R are true and R is correct explanation of A |
| D. | Both A and R are true and R is not the correct explanation of A |
| Answer» B. | |
| 1674. |
A network has 10 nodes and 17 branches. The number of different node pair are |
| A. | 7 |
| B. | 9 |
| C. | 10 |
| D. | 45 |
| Answer» C. 10 | |
| 1675. |
A parallel plate capacitor with air as dielectric has a capacitance C. If the dielectric has a dielectric constant ‚ààr and the remaining dimensions are the same, the capacitance will be |
| A. | C/‚ààr |
| B. | ‚ààrC |
| C. | ‚àà2rC |
| D. | ‚àà3rC |
| Answer» C. ‚àà2rC | |
| 1676. |
In an RC series circuit R = 100 Ω and XC = 10 Ω. In this circuit |
| A. | the current and voltage are in phase |
| B. | the current leads the voltage by about 6° |
| C. | the current leads the voltage by about 84° |
| D. | the current lags the voltage by about 6° |
| Answer» C. the current leads the voltage by about 84¬∞ | |
| 1677. |
Which pair is correctly matched? |
| A. | Symmetrical two port AD - BC = 1 |
| B. | Reciprocal two port z11 = z12 |
| C. | Inverse hybrid parameter A, B, C, D |
| D. | hybrid parameter (V1, I2) = f(I1, V2) |
| Answer» E. | |
| 1678. |
In figure, the steady state current through 1H inductance is |
| A. | Zero |
| B. | 0.125 |
| C. | 0.20833333333333 |
| D. | 0.25 |
| Answer» C. 0.20833333333333 | |
| 1679. |
In low pass filter of figure R0 = 1 Ω and cut off frequency is 1 rad/sec. The values of L and C are |
| A. | 1 H and 2 F |
| B. | 1 H and 1 F |
| C. | 2 H and 1 F |
| D. | 1 H and 2 F |
| Answer» E. | |
| 1680. |
The response shown in figure is |
| A. | over damped |
| B. | critically damped |
| C. | under damped |
| D. | either (a) or (c) |
| Answer» D. either (a) or (c) | |
| 1681. |
Given Is = 20 A, Vs = 20 V, the current I in the 3 Ω resistance is given by |
| A. | 0.16666666666667 |
| B. | 0.33333333333333 |
| C. | 0.083333333333333 |
| D. | 16 A |
| Answer» B. 0.33333333333333 | |
| 1682. |
The capacitance of a cylindrical capacitor is directly proportional to its length. |
| A. | 1 |
| B. | |
| C. | 1 |
| D. | |
| Answer» B. | |
| 1683. |
As the diameter of a wire is doubled, the resistance becomes |
| A. | twice |
| B. | one half |
| C. | one fourth |
| D. | four times |
| Answer» D. four times | |
| 1684. |
A current is flowing through a conductor with non-uniform area of cross-section. Then |
| A. | current will be different at different cross-sections. |
| B. | current will be the same at all the cross-sections. |
| C. | current will be different but current density will be same at all the cross-sections |
| D. | current will be the same but current density will be different at different cross-sections. |
| Answer» E. | |
| 1685. |
In any network of linear impedances the current flowing at any point equal to algebric sum of currents caused to flow at that point by each of the emf taken separately with all other emfs reduced to zero. The statement represents. |
| A. | KCL |
| B. | Norton's theorem |
| C. | Thevenin's theorem |
| D. | Superposition theorem |
| Answer» B. Norton's theorem | |
| 1686. |
The opposition of an inductor to current flow |
| A. | depends only on the resistance of the coil |
| B. | depends on the magnitude of the applied voltage |
| C. | varies directly with frequency |
| D. | varies inversely with frequency |
| Answer» D. varies inversely with frequency | |
| 1687. |
In using mesh current method it is necessary that at least one mesh current links every element. |
| A. | 1 |
| B. | |
| Answer» B. | |
| 1688. |
Z(c) for the network shown in the figure is The value of C and R are, respectively |
| A. | 1/6 F and 4 Ω |
| B. | 2/9 F and 9/2 Ω |
| C. | 2/3 F and 1/2 Ω |
| D. | 1/2 F and 1 Ω |
| Answer» B. 2/9 F and 9/2 Œ© | |
| 1689. |
A material for permanent magnet should have |
| A. | High retentivity |
| B. | High permeability |
| C. | Low hysteresis loss |
| D. | High hysteresis loss |
| Answer» B. High permeability | |
| 1690. |
The minimum permissible size of aluminium cable for lighting circuit is |
| A. | 1.2 sq. mm |
| B. | 1.5 sq. mm |
| C. | 2.2 sq. mm |
| D. | 3.5 sq. mm |
| Answer» C. 2.2 sq. mm | |
| 1691. |
In figure, the voltage V1 = 4∠0 V. The source voltage V2 is |
| A. | 8 - j8 volts |
| B. | 4 - j4 volts |
| C. | 8 - j4 volts |
| D. | 8 - j16 volts |
| Answer» D. 8 - j16 volts | |
| 1692. |
How much r.m.s. current does a 300 W, 200 V bulb take from the 200V, 50 Hz power line? |
| A. | 0.5 A |
| B. | 1.5 A |
| C. | 0.083333333333333 |
| D. | 0.125 |
| Answer» C. 0.083333333333333 | |
| 1693. |
One commercial unit of energy is equal to |
| A. | 1 watt-sec |
| B. | 1 kilowatt-sec |
| C. | 1 kilowatt-hour |
| D. | One watt-hour |
| Answer» D. One watt-hour | |
| 1694. |
A step voltage E is applied to a series R-L circuit. The rate of change of current is maximum at t = |
| A. | zero |
| B. | infinity |
| C. | L/R |
| D. | R/L |
| Answer» B. infinity | |
| 1695. |
Which of the following pairs are correctly matched? Brune's realisation : realisation with ideal transformer.Cauer realisation : ladder realisation.Bott Duffin realisation : with non ideal transformer. Select the answer using the following codes: |
| A. | 1, 2 and 3 |
| B. | 2 and 3 |
| C. | 1 and 3 |
| D. | 1 and 2 |
| Answer» E. | |
| 1696. |
The function (s + 2) (s + 4)/[(s + 1)(s + 3)] |
| A. | is a reactance function |
| B. | is an RC function |
| C. | may be a reactance function or an RC function |
| D. | may be RC function or an RL function |
| Answer» E. | |
| 1697. |
A parallel resonant circuit can be used |
| A. | as a high impedance |
| B. | to reject a small band of frequencies |
| C. | both (a) and (b) |
| D. | to amplify certain frequencies |
| Answer» D. to amplify certain frequencies | |
| 1698. |
An RLC series circuit is fed form 100 V ac supply. Inductance is 1 H and Q = 7.5. At resonance, the voltage across inductance is |
| A. | 750 V |
| B. | 100 V |
| C. | about 13.5 V |
| D. | 1500 V |
| Answer» B. 100 V | |
| 1699. |
In a driving point function poles and zeros must be conjugate if complex or imaginary. |
| A. | 1 |
| B. | |
| C. | nickel cadmium battery |
| D. | lead acid battery |
| Answer» B. | |
| 1700. |
A choke coil has a resistance to reactance ratio of 0.2. The power factor of the choke coil is |
| A. | less than 0.2 lagging |
| B. | less than 0.2 leading |
| C. | about 1 |
| D. | about 0 |
| Answer» B. less than 0.2 leading | |