$1-$ Which of the following has minumum error detetcion Select one:

a$.$ QPSK

b$.4$PSK

c$.$ BPSK

d$.8$PSK

$2-$ Quantization noise can be increased by $\_\_\_\_\_\_\_\_$ the number of levels. Select one:

a$.$ Decreasing

b$.$ Increasing

c$.$ Doubling

d$.$ Squaring

$3-$ A carrier wave of frequency $100$ MHz is frequency modulated $($DSBSC$)$ by sinusoidal wave $($ information signal $)$ of amplitude $20$ volts and frequency $10$ KHz$.$ The Bandwidthof the modulator is Select one:

a$.40$ KHZ

b$.200$ KHZ

c$.400$ KHZ

d$.4$ KHZ

$4-$ A sampling rate of $................$ million samples per seconds is needed for a signal with components ranging from $10$ MHz to $100$ MHz$.$ Select one:

a$.10$

b$.90$

c$.100$

d$.200$

$5-$ The quantization noise in PCM has: Select one:

a$.$ Gaussian distribution

b$.$ Uniform distribution

c$.$ Exponential distribution

d$.$ Bessel function