Which is called as on-off keying?

• Amplitude shift keying

• Uni-polar PAM

• Amplitude shift keying & Uni-polar PAM

• None of the mentioned

Which of the following are the advantages of digital modulation?

• Finite process

• Higher noise immunity

• Multiplexing property

• All the above

Which of the following are the digital modulation techniques?

• ASK

• PSK

• FSK

• All the above

Which of the following are the formulas of carrier signals in FM 2by 1 mux?

• Ac Cos (2wc+ Θ)t

• Ac Cos (2wc - Θ)t

• Ac Cos (2wcΘ)t

• Both a and b

M- ary digital technique transmits ____ number of bits per time?

• 1

• 2

• 0

• >2

A carrier signal is of ___ wave shape?

• Sine

• Rectangle

• Triangle

• Pulse

In DPSK technique, the technique used to encode bits is

• AMI

• Differential code

• Uni polar RZ format

• Manchester format

QPSK system uses a phase shift of

• Π

• Π/2

• Π/4

• 2Π

The data rate of QPSK is ___________ of BPSK.

• Thrice

• Four times

• Twice

• Same

QPSK is a modulation scheme where each symbol consists of

• 4 bits

• 2 bits

• 1 bits

• M number of bits, depending upon the requirement