SESSIONAL QUESTION PAPER FOR ECN SUBJECT

First sessional  Examination 2016-17

Sub-ECN  Sub code- 17323    Max  mark 25       Time 1Hr

Que 1. Attempt any three (3*3=9M)

1) State the terms instantaneous value and maximum value of an alternating quantity.

2) Define power factor and state its value for pure resistive circuits.

3) Define the terms admittance and susceptance. State their units.

4) Define rms value, average value and form factor.

Que 2. Attempt any two (4*2=8M)

1) Draw impedance triangle and voltage phasor diagram for R-L series circuits.

2) Define the following terms with reference to alternating quantity.

i) Waveform ii) Cycle iii) Frequency iv) Time period

3) A 318µF capacitor is connected across a 230V, 50Hz system. Determine: (i) Capacitive reactance (ii) RMS value of current  (iii) Equation for voltage (iv) Equation for current

Que 3. Attempt any two(4*2=8M)

1) Draw waveform and write equation for voltage and current for a AC circuit containing capacitance only.

2) A capacitor having capacitance of 20 µF is connected in series with a non-inductive

resistance of 120 Ω, across 100V, 50 Hz supply. Calculate: (i) Current, (ii) The phase difference between voltage and current, (iii) The power. Also draw the vector diagram.

3) An e.m.f. source represented by e=20 sin 314t is connected to a pure inductance having value 10mH. Find:

(i)  The equation of current flowing through it.

(ii)  Draw the waveforms of voltage and current.