Wireless PSI / TO paper 3

Electronics & Communication Mock Test

Topics: Diode, Transistors, Bridges, Modulation, Radar & Networks

1. A Zener diode is primarily used for:

Rectification Voltage Regulation Amplification Filtering Not Attempted

2. In a BJT, the relation between alpha (α) and beta (β) is:

β = α / (1 - α) α = β / (1 - β) β = α / (1 + α) α = 1 + β Not Attempted

3. Which biasing circuit provides the highest stability for a BJT?

Fixed Bias Collector to Base Bias Self Bias (Voltage Divider Bias) Emitter Bias Not Attempted

4. A Lossless Transmission Line has a characteristic impedance (Zo) equal to:

√(L/C) √(C/L) 1/√(LC) R + jωL Not Attempted

5. The modulation index of Amplitude Modulation (AM) is kept below 1 to avoid:

Attenuation Over-modulation and Distortion Frequency Shifting Noise interference Not Attempted

6. Which layer of the OSI model is responsible for routing?

Data Link Layer Network Layer Transport Layer Physical Layer Not Attempted

7. De Morgan's first law states that (A + B)' is equal to:

A' + B' A' . B' A . B (A . B)' Not Attempted

8. In FM, the frequency deviation is proportional to:

Modulating Signal Amplitude Modulating Signal Frequency Carrier Frequency Carrier Amplitude Not Attempted

9. Wheatstone bridge is used to measure:

Medium Resistance High Capacitance Low Inductance Frequency Not Attempted

10. The Standing Wave Ratio (SWR) for a perfectly matched line is:

0 1 Infinity -1 Not Attempted

11. A Class A amplifier has a maximum theoretical efficiency of:

78.5% 25% (Series fed) 100% 50% Not Attempted

12. The term "Duplexer" in Radar is used to:

Use same antenna for TX and RX Increase range Filter noise Measure Doppler shift Not Attempted

13. In Phase Modulation (PM), the phase deviation is proportional to:

Modulating Signal Amplitude Modulating Signal Frequency Square of frequency Integral of frequency Not Attempted

14. Schering Bridge is used to measure:

Inductance Capacitance Resistance Frequency Not Attempted

15. The Boolean expression A + AB equals:

A B A+B 1 Not Attempted

16. MAC address operates at which layer?

Data Link Network Session Physical Not Attempted

17. Which diode is used as a voltage-variable capacitor?

Tunnel Diode Varactor Diode LED Zener Diode Not Attempted

18. A Common Collector amplifier is also known as:

Voltage Follower Emitter Follower Base Follower Phase Splitter Not Attempted

19. In a transmission line, when the load impedance equals characteristic impedance, the reflection coefficient is:

0 1 -1 0.5 Not Attempted

20. Which gate is known as the "Universal Gate"?

AND NAND OR XOR Not Attempted

21. The "Skin Effect" in conductors increases with:

Higher Frequency Lower Frequency Direct Current (DC) Increased Temperature only Not Attempted

22. TCP is a _______ protocol.

Connection-oriented Connectionless Best-effort Hardware-level Not Attempted

23. In a Programmable Logic Array (PLA):

Both AND and OR arrays are programmable Only AND array is programmable Only OR array is programmable Neither array is programmable Not Attempted

24. Which bridge is used for the measurement of an unknown Inductance in terms of Capacitance?

Wheatstone Bridge Maxwell-Wien Bridge Schering Bridge Wien Bridge Not Attempted

25. In Radar systems, the 'Pulse Repetition Frequency' (PRF) determines:

Radar Resolution Maximum Unambiguous Range Target Cross-section Minimum Range Not Attempted

26. The Doppler effect in Radar is used to measure:

Target Shape Target Distance Relative Velocity of target Atmospheric pressure Not Attempted

27. Which of the following is a 'Direct' method of generating FM?

Varactor Diode Modulator Armstrong Method Phase Shift Method Frequency Discriminator Not Attempted

28. In Computer Networks, the 'Subnet Mask' is used to:

Identify the MAC address Distinguish Network ID from Host ID Speed up data transfer Encrypt the packet Not Attempted

29. A negative feedback amplifier always has a:

Reduced Bandwidth Improved Stability Increased Distortion Higher Gain Not Attempted

30. Which Boolean law states that A + (B . C) = (A + B) . (A + C)?

Associative Law Commutative Law Distributive Law Idempotent Law Not Attempted