MCQOPTIONS
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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.
| 251. |
A circuit is fed by two sources of different frequency and magnitudes 100 ∠0° V and 50 ∠30°V. The current in a particular branch is 10 ∠20° A. If the magnitudes of the sources are changed to 200 ∠0° V and 100 ∠0° V, the current in that branch should be |
| A. | 20 ∠20° A |
| B. | 10 ∠20° A |
| C. | 14.14 ∠20° A |
| D. | 10 ∠- 20° A |
| Answer» B. 10 ∠20° A | |
| 252. |
The equivalent resistance between terminals x and y figure |
| A. | 150 Ω |
| B. | 45 Ω |
| C. | 55 Ω |
| D. | 35 Ω |
| Answer» E. | |
| 253. |
Consider the followingIf a network has impedance (1 - j) at a specific frequency, the circuit would consists of series 1. R and C2. R and L3.R, L and C Which of these statements is correct? |
| A. | 1 and 2 |
| B. | 1 and 3 |
| C. | 1, 2 and 3 |
| D. | 2 and 3 |
| Answer» E. | |
| 254. |
A two-port network is represented by ABCD parameters given by following equation. If port is terminated by RL, then input impedance seen at port 1 is given by |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 255. |
In the circuit shown in the given figure, power dissipated in the 5 Ω resistor is |
| A. | zero |
| B. | 80 W |
| C. | 125 W |
| D. | 405 W |
| Answer» E. | |
| 256. |
Assertion (A): In a circuit having high inductance, reactive power may be more than apparent power.Reason (R): Reactive power = VI sin θ. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true and R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» E. | |
| 257. |
In a lead acid battery |
| A. | the numbers of positive and negative plates are equal |
| B. | the number of positive plates may be equal to or more than the number of negative plates |
| C. | the number of positive plates is more than the number of negative plates |
| D. | the number of negative plates is more than the number of positive plates |
| Answer» E. | |
| 258. |
A 10 μF capacitor is charged from a 5 volt source through a resistance of 10 kΩ. The charging current offer 35 m sec. If the initial voltage on C is - 3 V is |
| A. | 0.56 mA |
| B. | 5.6 mA |
| C. | 6 mA |
| D. | 5 μA |
| Answer» B. 5.6 mA | |
| 259. |
An RLC series circuit has Y(s) = 2s/(s-p₁)(s-p₁*). If the poles p1 and p1* are close to jω axis, then |
| A. | Q is high |
| B. | Q is low |
| C. | ω₀ is high |
| D. | bandwidth is large |
| Answer» E. | |
| 260. |
Transient current in an RLC circuit is oscillatory when |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 261. |
A series circuit has R = 5 Ω and C = 10 μF. It is switched on to a 12 V dc battery at t = 0. The current in the circuit will be maximum |
| A. | at t = RC |
| B. | at t = ∞ |
| C. | at t = 0+ |
| D. | none of the above |
| Answer» D. none of the above | |
| 262. |
In a RL circuit, the angle, θ by which the current lags the voltage is |
| A. | 0 > θ > - 90° |
| B. | 90° |
| C. | 0° |
| D. | 0 < θ < 90° |
| Answer» E. | |
| 263. |
If Ia, Ib, Ic are line currents and Ia2 is the negative sequences component of Ia then |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 264. |
If a resistance R of 1 Ω is connected between A and B in figure, current flowing through R is |
| A. | 1 A |
| B. | 0.5 A |
| C. | 0.25 A |
| D. | 0.125 A |
| Answer» D. 0.125 A | |
| 265. |
The following function |
| A. | is a reactance function |
| B. | is an RC function |
| C. | is an RL function |
| D. | may be reactance function or RC function |
| Answer» B. is an RC function | |
| 266. |
In ZRC (s) has a pole at s = ∞, the last element in first Foster realization is |
| A. | R |
| B. | C |
| C. | R and C in series |
| D. | R and C in parallel |
| Answer» B. C | |
| 267. |
A two branch parallel circuit has a 10 Ω resistance and 0.5 H inductance in one branch and a 100 μF capacitor in the second branch. It is fed from 100 V ac supply. At resonance, the source current is |
| A. | 10 A |
| B. | 1 A |
| C. | 0.2 A |
| D. | 0.05 A |
| Answer» D. 0.05 A | |
| 268. |
Which of the following pairs are correctly matched? 1. Brune's realisation : realisation with ideal transformer.2. Cauer realisation : ladder realisation.3. 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. | |
| 269. |
Choose the correct option 1. Transit period is the time between two steady state2. Transient Response is the response due to internal energy stored in circuit3. Transit response is also called natural response4. Transit response arises due to presence of C and L in the circuit5. Transit is due to R, L, C in the circuit |
| A. | 4, 3, 2 , 1 |
| B. | 5, 4, 3, 2 |
| C. | 5, 4, 3, 1 |
| D. | 5, 1, 4 |
| Answer» B. 5, 4, 3, 2 | |
| 270. |
A sine wave of voltage varies from zero to maximum of 200V. How much is the voltage at the instant of 30° of the cycle? |
| A. | 50 V |
| B. | 82.8 V |
| C. | 100 V |
| D. | 173.2 V |
| Answer» D. 173.2 V | |
| 271. |
KVL for second loop in figure is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» C. C | |
| 272. |
The Laplace transform of i(t) is given by following equation. As t → ∞ the value of i(t), tends to |
| A. | 0 |
| B. | 2 |
| C. | 1 |
| D. | ∞ |
| Answer» C. 1 | |
| 273. |
Consider the following statements:1. Tellegen's theorem is applicable to any lumped network.2. Reciprocity theorem is applicable to linear bilateral network.3. Thevenin theorem is applicable to two terminal linear active network.4. Norton's theorem is applicable to linear active network. Which of the above statements are correct? |
| A. | 1, 2 and 3 |
| B. | 1, 2, 3 and 4 |
| C. | 1, 2 and 4 |
| D. | 3 and 4 |
| Answer» C. 1, 2 and 4 | |
| 274. |
Which one of the following theorem can be conveniently used to calculate the power consumed by the 10 Ω resistor in the network shown in the above figure? |
| A. | Thevenin's theorem |
| B. | Maximum power transfer theorem |
| C. | Millman's theorem |
| D. | Superposition theorem |
| Answer» E. | |
| 275. |
Which of the following theorems can be conveniently used to find power consumed in 10 Ω resistor in figure? |
| A. | Thevenin theorem |
| B. | Maximum power transfer theorem |
| C. | Millman's theorem |
| D. | Superposition theorem |
| Answer» E. | |
| 276. |
The dual of network in figure is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 277. |
Choose the correct option1. Mesh is the smallest loop of circuit2. Loop is smallest path of circuit3. Loop does not contain any mesh4. Loop may have one or more than one mesh |
| A. | 1, 2, 3, 4 |
| B. | 3, 4, 2 |
| C. | 1, 4 |
| D. | 3, 2 |
| Answer» D. 3, 2 | |
| 278. |
Choose the correct option |
| A. | tree does not contain any loop |
| B. | tree contain all the nodes |
| C. | tree is always open |
| D. | all |
| Answer» E. | |
| 279. |
In figure, V1 = 40 V when R = 10 Ω, if R = 0, V2 will be |
| A. | 40 V |
| B. | 30 V |
| C. | 20 V |
| D. | 10 V |
| Answer» D. 10 V | |
| 280. |
Which of the following is an I.S.I. symbol of cut-out power? |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» E. | |
| 281. |
A cable has an insulation resistance of 10¹ᴼ ohms. If the length is doubled, the insulation resistance will be |
| A. | 2 x 10¹ᴼ Ω |
| B. | 0.5 x 10¹ᴼ Ω |
| C. | 10¹ᴼ Ω |
| D. | 4 x 10¹ᴼ Ω |
| Answer» C. 10¹ᴼ Ω | |
| 282. |
If Y(s) = s² + 1/s , the network has |
| A. | 1 H inductor and 1 F capacitor in parallel |
| B. | 1 H inductor and 1 F capacitor in series |
| C. | 1 H inductor and 1 Ω resistor in series |
| D. | 1 H inductor and 1 Ω resistor in parallel |
| Answer» B. 1 H inductor and 1 F capacitor in series | |
| 283. |
For the current wave i = 10 + 10 sin θ, the rms value is |
| A. | 10 A |
| B. | 12.247 A |
| C. | 20 A |
| D. | 14.14 A |
| Answer» C. 20 A | |
| 284. |
In the circuit of figure. The current supplied by battery at t = ∞ is |
| A. | 0 A |
| B. | 5 A |
| C. | less than 5 A |
| D. | very large |
| Answer» C. less than 5 A | |
| 285. |
The hot resistance of a tungsten lame is about 12 times its cold resistance. Accordingly, the cold resistance of a 60 Ω, 120 V lamp is about __________ ohm. |
| A. | 5 |
| B. | 240 |
| C. | 2 |
| D. | 2880 |
| Answer» D. 2880 | |
| 286. |
As B is increased from zero to about 2T, μᵣ, of a ferromagnetic material |
| A. | increase |
| B. | decrease |
| C. | first increases then decreases |
| D. | remains the same |
| Answer» D. remains the same | |
| 287. |
For the R-L circuit shown in the figure, the input voltage vi(t) = U(t). The current i(t) is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 288. |
In the circuit shown, the steady state is reached with S open S is closed at t = 0, the current I in the 1 Ω resistor connected is to be determined at t = 0+ is given by |
| A. | 1 |
| B. | 2 |
| C. | 3 |
| D. | 4/3 |
| Answer» B. 2 | |
| 289. |
The polynomial P (s) = (s - 1) (s² + 1) (s + 2) (s + 3) is |
| A. | Hurwitz but not strictly Hurwitz |
| B. | not Hurwitz |
| C. | strictly Hurwitz |
| D. | anti/Hurwitz |
| Answer» D. anti/Hurwitz | |
| 290. |
A capacitor whose capacitance Ct = C₀ (1- cos ωt) is fed by a sinusoidal voltage v = V₀ sin ωt. The equation for current i is |
| A. | ω C₀V₀ cos ωt |
| B. | ω C₀V₀ sin ωt |
| C. | ω C₀V₀ (cos ωt - cos² ωt) |
| D. | none of the above |
| Answer» D. none of the above | |
| 291. |
For figure, the incidence matrix A is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» D. D | |
| 292. |
If A = 16 ∠64°, (A)^0.5 is |
| A. | 4∠64° |
| B. | 4∠8° |
| C. | 4∠128° |
| D. | 4∠32° |
| Answer» E. | |
| 293. |
S is closed for a long time and steady state is reached. S is opened at t(0-). The voltage marked V is V0 at t = 0+ and Vf at t = ∞. Then value of V0 and Vf are respectively |
| A. | 8, 8 |
| B. | 0, 1 |
| C. | 4, 0 |
| D. | 4, 8 |
| Answer» E. | |
| 294. |
If e = 110 sin (ωt + π/3) and i = 5 sin (ωt - π/3), the impedance of the circuit is |
| A. | 22 Ω |
| B. | 16 Ω |
| C. | 30.8 Ω |
| D. | 11 Ω |
| Answer» B. 16 Ω | |
| 295. |
A series resonant circuit has parameters 10 ω, 1 H and 0.1 F. It is excited by a voltage v = 100 sin ωt. At resonant frequency, the power dissipated in the circuit is |
| A. | 1000 W |
| B. | 707 W |
| C. | 500 W |
| D. | 414.14 W |
| Answer» D. 414.14 W | |
| 296. |
The inductance of an air cored coil is 2 H. The number of turns is made 3 times, all other quantities remaining the same. The new value of inductance will be 2 2 |
| A. | 2H/9 |
| B. | 2H/3 |
| C. | 6 H |
| D. | 18 H |
| Answer» E. | |
| 297. |
A system defined by dy/dt + y = x is initially at rest, and x = u(t) sin 2t then the forced response is K sin (2t - θ). The value of θ given by |
| A. | -tan¯¹(1) |
| B. | -tan¯¹(2) |
| C. | -tan¯¹(1/2) |
| D. | 0 |
| Answer» C. -tan¯¹(1/2) | |
| 298. |
The average value of periodic function v(t) in figure is |
| A. | A |
| B. | B |
| C. | C |
| D. | D |
| Answer» B. B | |
| 299. |
The capacitance of a parallel plate capacitor varies as per the equation C(t) = C₀ (1 - cos ωt). It is connected to a battery of V volts. The equation for current is |
| A. | ωC₀V (1 - cos ωt) |
| B. | ωC₀V(1 - sin ωt) |
| C. | ωC₀V (1 - sin 2ωt) |
| D. | ωC₀V sin ωt |
| Answer» E. | |
| 300. |
A series circuit having R = 3 Ω and L = 2 H is excited by a 10 V battery. At t = 0+, di/dt is |
| A. | 5 A/s |
| B. | 10/3 A/s |
| C. | 20 A/s |
| D. | 15 A/s |
| Answer» B. 10/3 A/s | |