21.For a paraboloidal reflector antenna, the reflector diameter is 6 m and the illumination efficiency is 0.65, frequency of operation is 10 GHz, its effective aperture area and 3 dB Bandwidth will be :
1. 18.4 m2 and 0.35°
2. 28.26 m2 and 0.35°
3. 0.48 m2 and 0.70°
4. 18.2 m2 and 0.70°
22. Si MBE is performed under Ultra-High Vacuum conditions with system pressure of 10-9 Torr. The mean free path of the atoms is:
1. 5 X 108 cm
2. 5 X 107 cm
3. 5 X 106 cm
4. 5 X 109 cm
23. Match List-I with List-II
|
List-I |
List-II |
|---|---|
|
A. Reflex klystron B. Magnetron C. TWT D. Multicavity Klystron |
I. High efficiency and High power II. Slow wave structure III. Cross field device IV. Oscillator |
Choose the correct answer from the options given below:
1. A-I, B-II, C-III, D-IV
2. A-IV, B-III, C-II, D-I
3. A-IV, B-II, C-I, D-III
4. A-III, B-I, C-IV, D-II
24. A 20 km optical fiber with LED output power of 20 mW and four, 5 Km section of optical fiber each with loss of 0.5 dB/Km. The values of LED output power in dBm and total cable loss respectively are:
1. 15 dBm, 10 dB
2. 13 dBm, 10 dB
3. 12 dBm, 20 dB
4. 10 dBm, 20 dB
25. The following statements are given about Programmable Logic Devices (PLDs). Select the correct ones.
A. The most common FPGA programming technology is SRAM, which is volatile.
B. PLDs are the most expensive type of ASIC (Application Specific Integrated Circuits) to develop.
C. SRAM programming technology provides a very high density of storage cells that are used to program larger PLDs.
D. ‘EEPROM’ and ‘FLASH’ are volatile.
Choose the correct answer from the options given below:
1. A and B only
2. A and C only
3. B and C only
4. B and D only
26. Which of the following are examples of direct addressing modes in context of 8051 microcontroller?
A. MOV R 0, 40 H
B. MOV 56 H, A
C. MOV DPTR, # 452 H
D. MOV A, # 44 H
E. MOV B, # 40 H
Choose the correct answer from the options given below:
1. A and B only
2. B and D only
3. A and C only
4. D and E only