GATE EC 1995 Electronics Question Paper
SECTION - A
1. For each of the following questions (1.1 œ 1.47), 4 alternatives, A, B, C
and D are given. Indicate the correct or the best answer by writing the
corresponding lable, A, B, C or D in CAPITALS against each question
num ber.
1.1 A DC voltage source is connected across a series R-L-C circuit. Under steady-state conditions, the applied DC voltage drops entirely across the
(a) R only (b) L only (c) C only
(d) R and L combination
1.2 Consider a DC voltage source connected to a series R-C circuit. When the steady state reaches, the ratio of the energy stored in the capacitor to the total energy supplied by the voltage source, is equal to
(a) 0.362 (b) 0.500 (c) 0.632 (d) 1.000
1.3 Two 2H inductance coils are connected in series and are also magnetically coupled to each other the coefficient of coupling being 0.1. The total inductance of the combination can be
(a) 0.4 H (b) 3.2 H (c) 4.0 H (d) 3.3 H
1.4 The RMS value of a rectangular wave of period T, having a value of +V for a ( ) T T < duration, and œV for the duration, T T T - = , equals
1.6 The value of the resistance, R, connected across the terminals, A and B, (ref. figure), which will absorb the maximum power, is
(a) 4.00 k (b) 4.11 k (c) 8.00 k (d) 9.00 k
1.7 The current, through a 10 by
i t t t 3 4 sin100 45 4 sin300 60 Amperes
The RMS value of the current and the power dissipated in the circuit are:
(a) 41 , A 410 W, respectively (b) 35 , A 350 W, respectively
(c) 5A, 250 W, respectively (d) 11A, 1210 W, respectively
1.8 Signal flow graph is used to find
(a) stability of the system (b) controllability of the system
(c) transfer function of the system (d) poles of the system
1.9 The step error coefficient of a system G s s s = + + with unity feedback is
1.10 The final value theorem is used to find the
(a) steady state value of the system output
(b) initial value of the system output
(c) transient behaviour of the system output
(d) none of these
1.11 For a second order system, damping ratio, is 0 1, < 0 K)
(a) 0 (b) 1 (c) 0.5 (d) 1.0
1.18 The drift velocity of electrons, in silicon
(a) is proportional to the electric field for all values of electric field
(b) is independent of the electric field
(c) increases at low values of electric field and decreases at high values of electric field exhibiting negative differential resistance.
(d) increases linearly with electric field at low values of electric field and gradually saturates at higher values of electric field.
1.19. The diffusion potential across a P-N junction
(a) decreases with increasing doping concentration
(b) increases with decreasing band gap
(c) does not depend on doping concentration
(d) increases with increase in doping concentrations
1.20. The breakdown voltage of a transistor with its base open is BV and that with emitter open is , BV then
(a) BV BV = (b) BV BV > (c) BV BV