Manipal University 2007 B.E Electrical and Electronics Engineering THIRD SEMESTER MAKE-UP (REVISED CREDIT SYSTEM) 05 ELECTRICAL CIRCUITS ( ELE 201 - Question Paper

THIRD SEMESTER B.E. DEGREE MAKE-UP exam
(REVISED CREDIT SYSTEM)
05 January 2007
ELECTRICAL CIRCUITS ( ELE 201

Department of Electrical and Electronics Engineering

Reg. No.:

MANIPAL INSTITUTE OF TECHNOLOGY, MANIPAL

(A Constituent Institute of MAHE, Deemed University)

THIRD SEMESTER B.E. DEGREE MAKE-UP EXAMINATION

(REVISED CREDIT SYSTEM)

05 January 2007 ELECTRICAL CIRCUITS ( ELE 201 )

Time: 3 hours    Max. Marks: 50

Note: Answer any FIVE full questions.

Q1A. In the network shown in Fig Q.No 1A, the switch is closed at t=0. Assuming zero initial conditions, find

i.    vi and v₂ at t = 0+ and at t=rc>

ii.    dv₁/dt and dv₂/dt at t= 0+.

-05-

Q1B. For the circuit shown in Fig. Q.No.iB, construct a tree in which V₁ and V₂ are the tree branch voltages. DetermineV₁ using cut set analysis.

-05-

Q2A. A communication system from a space station uses short pulses to control a robot operating in space. The transmitter circuit is modeled as in Fig. Q.No. 2A. Find the output voltage v_c(t) for t>0. Assume steady state condition at t=0 ^-.

-06-

Q2B. Find the branch currents i_o through i₄ for the circuit shown in Fig. Q.No. 2B. using

mesh current analysis    -04-

Q3A. Deduce the expressions for half power frequencies of a series RLC circuit. Also, show that the resonant frequency is the geometric mean of half power frequencies.

-05-

Q3B. For the locus diagram shown in Fig.Q No. 3B, draw the circuit configuration showing the element values. Also, find the value of R at unity power factor.

-05-

Q4A. For the circuit shown in Fig. Q. No.4A, find the voltage across the 4 Q reactance using superposition theorem. Assume X_M = 2 Q.    -07-

Q4B. Using admittance method, show that the circuit shown in fig.Q 4B, will not resonate for any value of X_L. Also, draw the locus diagram.    -03-

Q5A. For the circuit shown in Fig Q.No.5A, determine the current flowing in the 5 Q resistor using Nortons theorem.

-06-

Q5B. For the circuit shown in Fig.Q.No.5B, determine 9 such that max power is transferred to the 10Q resistor.    -04-

Q6A. A 3, 3 wire, RYB sequence supply system supplies power to a star connected load consisting of Zr = 10Z0 Q, Zy = 15Z30⁰ Q and Zb = 10Z-30⁰ Q. If Vbc = 208Z0⁰ V, determine the line currents and the total power consumed using the mesh current method. Also draw the phasor diagram representing all the quantities.    -05-

Q6B. For the circuit shown in Fig.Q.No.6B, determine the readings of the two wattmeters assuming an RYB phase sequence.    -05-

7i2
100V		6.5A
Fig. Q.No.2B

Fig. Q4(A)

Fig. Q3(B)

Fig. Q4(B)