For the following feedback system The 2% settling time of the
step response is required to be less than 2 seconds.

**A. ** 3(1/s + 5)

**B. ** 5((0.03/s) + 1)

**C. ** 2(s + 4)

**D. ** 4((s + 8) / (s + 3))

**Answer : ****Option C**

**Explaination / Solution: **

No Explaination.

No Explaination.

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A discrete time signal x[n] = sin (π^{2}n) n being an integer, is

**A. ** periodic with period π

**B. ** periodic with period π^{2}

**C. ** periodic with period π/2

**D. ** not periodic

**Answer : ****Option D**

**Explaination / Solution: **

In the given options (A), (B) and (C), we have the periods respectively as

In the given options (A), (B) and (C), we have the periods respectively as

N1 = π

N2 = π^{2}

N3 = π/3

None of the above period is an integer. Since, a discrete time signal has its period
an integer. So, all the three options are incorrect. Hence, we are left with the
option (D). i.e. the discrete time signal x[n] = sin (π^{2}n) is not periodic.

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The force on a point charge +q kept at a distance d from the surface of an infinite grounded metal plate in a medium of permittivity 𝜖 i

**A. ** 0

**B. ** away from the plate

**C. ** towards the plate

**D. ** towards the plate

**Answer : ****Option C**

**Explaination / Solution: **

Consider the point charge +q and infinite surface as shown below.

Consider the point charge +q and infinite surface as shown below.

We can replace the image charge by a negative equivalent charge -q placed at
2d distance from +q charge

Hence, the force experienced by +q charge is

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For maximum power transfer between two cascaded sections of an electrical
network, the relationship between the output impedance Z_{1} of the first section
to the input impedance Z_{2} of the second section is

**A. ** Z_{2} = Z_{1}

**B. ** Z_{2} = -Z_{1}

**C. **
**D. **
**Answer : ****Option C**

**Explaination / Solution: **

Consider the cascaded network shown below

Z_{2} = Z_{1}^{*}

Z_{2} = -Z_{1}^{*}

Consider the cascaded network shown below

Since, the output impedance of system 1 is Z_{1} and input impedance of system 2
is Z_{2}. So, we have the equivalent circuit is

Now, we consider a circuit with internal impedance Z_{in} and load impedance Z_{L}

For maximum power transfer, the condition is

Z_{in}^{* }= Z_{2}

Comparing this condition to cascaded system, we have the required condition for
maximum power transfer as

Z_{1}^{* }= Z_{2}

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Consider the configuration shown in the figure which is a portion of a larger
electrical network

**A. ** i6 = 5A

**B. ** i3 = -4A

**C. ** Data is sufficient to conclude that the supposed currents are impossible

**D. ** Data is insufficient to identify the currents i_{2}, i_{3} and i_{6}

**Answer : ****Option A**

**Explaination / Solution: **

From the circuit, we have

For R = 1Ω and currents i_{1} = 2 A, i_{4} =- 1 A, i_{5} =- 4 A, which one of the
following is TRUE ?

From the circuit, we have

i_{2} = i_{4} + i_{1}

= -1 + 2

= 1A

i_{3} = i_{5} + i_{2}

= -4 + 1

= -3A

i_{6} = i_{1} – i_{3}

= 2 - (-3)

= 5A

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A two-port network has scattering parameters given by If the
port-2 of the two port is short circuited, the S_{11} parameter for the resultant one

**A. **

**B. **

**C. **

**D. **

**Answer : ****Option B**

**Explaination / Solution: **

No Explaination.

No Explaination.

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A 230 V rms source supplies power to two loads connected in parallel. The first load draws 10 kW at 0.8 leading power factor and the second one draws 10 kVA at 0.8 lagging power factor. The complex power delivered by the source is

**A. ** (18 + j1.5) kVA

**B. ** (18 - j1.5) kVA

**C. ** (20 + j1.5) kVA

**D. ** (20 - j1.5) kVA

**Answer : ****Option B**

**Explaination / Solution: **

Consider the circuit diagram for given problem as shown below

Consider the circuit diagram for given problem as shown below

Load delivered to Z1 is

P_{1} = 10 kW

cos ϕ_{1}
= 0.8, leading

So, we obtain the complex power delivered to Z1 as

Again, the delivered power to load Z2 as

|s1|= 10 kVA

cos ϕ2 = 0.8, lagging

So, we obtain the complex power delivered to load Z2 as

Hence, the total complex power delivered by the source is

s_{1} + s_{2} = (10 – j7.5) + (8
+ j6)

= (18 - j1.5) kVA

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You are given three coins: one has heads on both faces, the second has tails on both faces, and the third has a head on one face and a tail on the other. You choose a coin at random and toss it, and it comes up heads. The probability that the other face is tails is

**A. ** 1/4

**B. ** 1/3

**C. ** 1/2

**D. ** 2/3

**Answer : ****Option B**

**Explaination / Solution: **

No Explaination.

No Explaination.

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For matrices of same dimension M , N and scalar c, which one of these properties DOES NOT ALWAYS hold ?

**A. **
**B. **
**C. **
**D. ** MN = NM

**Answer : ****Option D**

**Explaination / Solution: **

Let the matrices

(M^{T})^{T} = M

(cM)^{T} = c(M)^{T}

(M + N)^{T} = M^{T}
+ N^{T}

Let the matrices

i.e. the property holds always

i.e. property does not hold always.

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C is a closed path in the z -plane by |z| = 3 The value of the integral is

**A. ** -4π(1 + j2)

**B. ** 4π(3 - j2)

**C. ** -4π(3 + j2)

**D. ** 4π(1 - j2)

**Answer : ****Option C**

**Explaination / Solution: **

Integral,

Integral,

So, we have the singularity

z j + 2 = 0

z =- 2j

Since, z = -2j lies inside |z| = 3. Therefore, using cauchy’s integral, we get

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