Network Theory And Analysis - Study Mode

Show All Answers

[#196] The current I in the circuit shown is

(A) -j1 A

(B) j1 A

(C) 0 A

(D) 20 A

Correct Answer

(A) -j1 A

[#197] The circuit shown in the figure is used to charge the capacitor C alternately from two current sources as indicated. The switches S 1 and S 2 are mechanically coupled and connected as follows. For 2nT ≤ t < (2n + 1)T, (n = 0, 1, 2 . . .) S 1 to P 1 and S 2 to P 2 . For (2n + 1)T ≤ t < (2n + 2)T, (n = 0, 1, 2 . . .) S 1 to Q 1 and S 2 to Q 2 . Assume that the capacitor has zero initial charge. Give that u(t) is a unit step function, the voltage V C (t) across the capacitor is given by

(A) $$sumlimits_{n = 0}^infty {{{left( { - 1} ight)}^n}tuleft( {t - nT} ight)} $$

(B) $$uleft( t ight) + 2sumlimits_{n = 1}^infty {{{left( { - 1} ight)}^n}left( {t - nT} ight)uleft( {t - nT} ight)} $$

(C) $$tuleft( t ight) + 2sumlimits_{n = 1}^infty {{{left( { - 1} ight)}^n}left( {t - nT} ight)uleft( {t - nT} ight)} $$

(D) $$sumlimits_{n = 0}^infty {left[ {0.5 - {e^{ - left( {t - 2nT} ight)}} + 0.5{e^{ - left( {t - 2n - T} ight)}}} ight]} $$

Correct Answer

(C) $$tuleft( t ight) + 2sumlimits_{n = 1}^infty {{{left( { - 1} ight)}^n}left( {t - nT} ight)uleft( {t - nT} ight)} $$

[#198] Consider the following statements regarding duality: 1. The dual networks are obtained for both AC and DC circuits and they are based on Kirchhoff's laws. 2. Dual circuits are not obtained in planar networks. 3. Two networks are said to be dual networks if mesh equations of one network have the same form as the nodal equation of the other. Which of the above statements are correct?

(A) 1 and 2 only

(B) 1 and 3 only

(C) 2 and 3 only

(D) 1, 2 and 3

Correct Answer

(B) 1 and 3 only

[#199] A current of 5 A in primary coil of a circuit is reduced to zero at a uniform rate in 10 -3 seconds. If coefficient of mutual inductance is 2 H, then the induced emf in the secondary coil is

(A) 10 -4 V

(B) 10 4 V

(C) 10 -6 V

(D) 10 6 V

Correct Answer

(B) 10 4 V

[#200] Which of the following bulbs will have the least resistance?

(A) 220 V, 60 W

(B) 220 V, 100 W

(C) 115 V, 60 W

(D) 115 V, 100 W

Correct Answer

(D) 115 V, 100 W