ISRO Interview Question

. If sampling frequency doubles then
a) Quantization noise decreases
b) Quantization density decreases
c) Quantization noise increases
d) Quantization density increases
2. Two signals of 2GHz and 4GHz are frequency modulated on same carrier 10 GHz. Find the ratio of frequency deviation if band widths of both are equal.
a) 1:2 b)2:1 c) 1:1 d) 1:4
3. Gray code of 111 is
4. 3X512+7X64+5X8+3 then value in binary form contains _______ number of 1’s.
a) 7 b) 6 c) 9 d) none
5. The 2’s compliment of decimal number 19 in 8-bit system is
a) 11101101
6) The high gain codes are
a) Turbo codes b) BCH codes c) R-S codes
7) BCH codes are of the type________
a) Convolutional type b) c)
8) Time constant of LC circuit is
a) L/R b) L/R2 c) RL
9) If R is doubled and C is halved then frequency of series RLC circuit is
10) The solution for the equation (D2+4) y=sin2x is
11) Laplace Tramsform of sin3x is
12) The Z-transform for the series is
X [n] = { 7; n= -1
{5 n=0
{ 1 n=1
{0 else
13) The magic Tee is a
a) 4 port tee b) c)
14) The register which holds the address of the next instruction is
a) Program counter b) c)
15) The antenna gain is given by……………?
a16) The satellite is in 630km orbit and transmitting at a frequency 5 MHz, when satellite is on your head the Doppler shift is——–
a) b) c) 0 d)
17) The impedance of a lossless transmission line is
a) ?(L/C)
18) A 50?line with load impedance 100? the VSWR is
19) In a waveguide measurement, the forward power is 10mW, the reverse power is 1mW then VSWR is _____________
20) Transmitted power is 100W, gain of the transmitter antenna is 30 dB and the path loss is 50 dB then received power is
21) When transmitted power is 100mW and the path loss 100 dBm then received power is
a) -80 dBm
22) When a em wave is incident normally on a perfect conductor then
a) Totally reflected b) partially reflected
c) Totally transmitted d) none.
23) Zsc =100? Zoc =1? then Zo is
a) 1? b) 10? c)___d)__
24) When the operating wavelength of line is ?/4< ? , the impedance is
a) Capacitive b) inductive c) ____ D) none
25) The value of L if source is 50V AC of 10 KHz frequency and current is 7.96 A.
a) ____