BARC ONLINE MOCK EXAM
a. instrumentation amplifiers
b. voltage followers
c. voltage regulators
2 The output voltage Vo of the above circuit is
3 The ideal OP-AMP has the following characteristics.
a) Ri=? ,A=? ,R0=0
b) Ri=0 ,A=? ,R0=0
c) Ri=? ,A=? ,R0=?
d) Ri=0 ,A=? ,R0=?
4 How many op-amps are required to implement this equation
5 A very brief, high voltage spike on an ac power line is called as
A. A bleeder
B. An arc
C. A transient
D. An avalanche
E. A clipped peak
6 You can find the zener diode in
A. The mixer in a superheterodyne receiver
B. The PLL in a circuit for detecting FM
C. The product detector in a receiver for SSB
D. The voltage regulator in a power supply
E. The AF oscillator in an AFSK transmitter
7 A network function can be completely specified by:
(A) Real parts of zeros
(B)Poles and zeros
(C)Real parts of poles
(D)Poles, zeros and a scale factor
8 A unit impulse voltage is applied to one port network having two linear components. If the current through the network is 0 for t<0 and decaysexponentially for t>0then the network consists of
(A) R and L in series
(B)R and L in parallel
(C)R and C in parallel
(D)R and C in series
9 The Q-factor of a parallel resonance circuit consisting of an inductance of value 1mH, capacitance of value 10-5 F and a resistance of 100 ohms is
(C) ? 20
10 In a travelling electromagnetic wave, E and H vector fields are
(A) perpendicular in space .
(B) parallel in space.
(C) E is in the direction of wave travel.
(D) H is in the direction of wave travel.
11 The lower cut -off frequency of a rectangular wave guide with inside dimensions (3 × 4.5 cm) operating at 10 GHz is
(A) 10 GHz.
12 The intrinsic impedance of free space is
(A) 75 ohm.
(C)120 ? ohm.
13 Which one of the following conditions will not guarantee a distortion less transmission line
(A)R = 0 = G
(B)RC = LG
(C) very low frequency range (R>> ? L, G >> ? C)
(D) very high frequency range (R<< ? L, G << ? C)
14 MOSFET can be used as a
(a) current controlled capacitor
(b) voltage controlled capacitor
(c) current controlled inductor
(d) voltage controlled inductors
15 In a common emitter, unbypassed resister provides
(a)voltage shunt feedback
(b)current series feedback
(c)negative voltage feedback
(d)positive current feedback
16 Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in
a) Only the temperature
b) only the ? of the transistor
c) Both Temperature & ?
d) None of the above
17 For the circuit shown in Fig.4, the voltage across the last resistor is V.All resistors are of ? 1 .The Vs is given by
18 The network has a network function Z(s)=s(s+2)/(s+3)(s+4)
(A)not a positive real function.
(C) RC network.
19 For a series R-C circuit excited by a d-c voltageof 10V, and with time-constant s, , ? the voltage across C at time ? = t is given by
20 A 2 port network using Z parameter representation is said to bereciprocal if