# Barc Sample Paper

Topics: Superheterodyne receiver, Hertz, Alternating current Pages: 7 (1343 words) Published: April 21, 2013
ELECTRONICS CAREER

www.ecatn.blogspot.com

BARC SAMPLE QUESTION PAPER FOR ELECTRONICS If you like my site please support us by sharing website (www.ecatn.blogspot.com) to your friends

1. Differential amplifiers are used in

a. instrumentation amplifiers b. voltage followers c. voltage regulators d. buffers 2.

The output voltage Vo of the above circuit is a. -6V b. -5V c. -1.2V d. -0.2V 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=∞

ELECTRONICS CAREER

www.ecatn.blogspot.com

4. . How many op-amps are required to implement this equation

A. 2 B. 3 C. 4 D. 1 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 t0then 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

ELECTRONICS CAREER

www.ecatn.blogspot.com

9. The Q-factor of a parallel resonance circuit consisting of an inductance

of value 1mH, capacitance of value 10-5F and a resistance of 100 ohms is (A) 1 (B)10 (C) π 20 (D) 100 10. In a travelling electromagnetic wave, E and H vector fields are

(A) (B) (C) (D)

perpendicular in space . parallel in space. E is in the direction of wave travel. H is in the direction of wave travel.

11. The lower cut-off frequency of a rectangular waveguide with inside

dimensions (3 × 4.5 cm) operating at 10 GHz is (A) 10 GHz. (B)9 GHz. (C) 10/9GHz. (D) 10/3GHz. 12. The intrinsic impedance of free space is

(A) 75 ohm. (B)73 ohm. (C)120 π ohm. (D)377ohm.
13. Which

one of the following conditions will not gurantee a distortionless transmission line (A)R = 0 = G (B)RC = LG (C) very low frequency range (R>> ω L, G >> ω C) (D) very high frequency range (R
www.ecatn.blogspot.com

(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 β of the transistor c) Both Temperature & β 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 Ω 1 . The Vs is given by

(A) 13V. (C) 4V.

(B) 8V. (D)1V.

18. The network has a network function Z(s)=s(s+2)/(s+3)(s+4)

(A)not a positive real function. (B)RL network. (C) RC network. (D)LC network. 19. For a series R-C circuit excited by a d-c voltageof 10V, and with time-

constant s, , τ the voltage across C at time τ = t is given by A. 10(1-e-1) v

ELECTRONICS CAREER

www.ecatn.blogspot.com

B. 10(2-e-2) v C. 10-e-1 volts D. 1-e-1
20. A 2 port network using Z parameter representation is said to be

reciprocal if A. Z11 =Z22 B. Z12 =Z21 C. Z12 = - Z21 D. Z11 – 2Z22 =0 21. Consider a transmission line of characteristic impedance 50 ohms and

the line is terminated at one end by +j50 ohms, the VSWR produced in the transmission line will be (A) +1 (C)infinity (B)zero (D)-1

22. In a certain medium E...