Ques.21. Diode resistance in case of forward biased in the ideal case. (SSC-2017)

Very very Low

Zero

Infinite

Very High

Answer.2. Zero

Explanation:

In ideal case diode resistance in forward biased acts as the perfect conductor and in reverse biased, it will act as the perfect insulator.

Therefore in an ideal case, the diode will offer zero resistance when forward biased.

Ques.22. If the resonant frequency of the circuit shown in figure I is 1 kHz, the resonant frequency of the circuit shown in figure II will be (SSC-2017)

4 KHz

2 KHz

0.05 kHz

0.25 kHz

Answer.2. 0.05 KHz

Explanation:

In figure second

Leq = 2L

Ceq = 2C

Ques.23. Two 100W, 200V lamps are connected in series across a 200V supply. The total power consumed by lamp will be watts? (SSC-2017)

25 W

200 W

50 W

150 W

Answer.3. 50 W

Explanation:

We know that

P = V^{2}/R

R = V^{2}/P

R = (200*200)/100 = 400 ohms

Since now the two bulbs are in series, the total resistance offered by them is : R’ = 400 Ω + 400 Ω = 800 Ω

Now the current that flows through either of them is :

I = V/R

= 200/800 = 0.25A

Since the bulbs are in series, the same amount of current flows through each of them.

Thus the power consumed by each lamp will be

P = I^{2}R

= (0.25)^{2} x 400

=25 Watt

The total power consumed by lamp = 25 x 2 = 50 watt

Ques.24. RC network shown in the figure can provide a maximum theoretical phase shift of (SSC-2017)

90°

180°

270º

360°

Answer.2. 180º

Explanation:

Each RC network Provides a phase shift of 60°. Now there are three RC network, Hence total phase shift will be 180°

Ques.25. What is I_{3}, I_{2}, I_{1}(SSC-2017)

5.5, 1.4, 1.1

1.1, 5.5, 1.4

5.5, 1.1, 1.4

1,2,3

Answer.2. 1.1, 5.5, 1.4

Explanation:

The current goes through all 3 resistors, so first we must calculate the total resistance. The formula for any number of resistors in parallel is 1/Rt = 1/R1 + 1/R2 + 1/R3

Ques.26. KCL is based on the concept of (SSC-2017)

Charge

Energy

Power

None of these

Answer.1. ChargeExplanation:

This law is also called Kirchhoff’s first law, Kirchhoff’s point rule, or Kirchhoff’s junction rule (or nodal rule).

The principle of conservation of electric charge implies that:

At any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node

Ques.27. What quantity of charge must be delivered by a battery with a potential difference of 110 V to 660 Joule of work? (SSC-2017)

0.6 C

6 C

60 C

600 C

Answer.2. 6C

Explanation:

electric potential difference P

P = W/Q

Q = W/P

= 660/110

= 6 C

Ques.28. Two 30 microfarad capacitor are connected in parallel, the resultant value of the capacitor in microfarad is: (SSC-2017)

60

15

90

45

Answer.1. 60

Explanation:

When capacitor is connected in parallel then the equivalent capacitance is C_{1} + C2

Therefore 30 + 30 = 60 μF

Ques.29. Which theorem is applicable for all types of network whether it is linear, unilateral bilateral, quadrilateral, active, passive, linear, non-linear. (SSC-2017)

Thevenin

Norton

Maximum power transfer theorem

Tellegen

Answer.4. Tellegen

Explanation:

Tellegen’s theorem is one of the most powerful theorems in network theory. The physical interpretation of Te|legen‘s theorem is the conservation of power. As per the theorem, the sum of powers delivered to or absorbed by all branches of a given lumped network is equal to 0 i.e. the power delivered by the active elements of a network is completely absorbed by the passive elements at each instant of time.

Tellegen’s theorem depends on KCL and KVL but not on the type of the elements. Tellegen theorem can be applied to any network linear or non-linear, active or passive, time-variant or time-invariant.

Ques.30. The quantity of a charge that will be transferred by a current flow of 10 A over 1 hour period is? (SSC-2017)