Systems

The type of systems which are characterized by input and the output quantized at certain levels are called as

• analog
• discrete
• continuous
• digital

A system is said to be defined as non causal, when

• the output at the present depends on the input at an earlier time
• the output at the present does not depend on the factor of time at all
• the output at the present depends on the input at the current time
• the output at the present depends on the input at a time instant in the future

Which one of the following is the correct statement ? The system characterized by the equation y(t) = ax(t) + b is

• linear for any value of b
• linear if b > 0
• linear if b < 0
• non-linear

Which one of the following systems described by the following input-output relations is non-linear ?

• y(n) = n x(2n)
• y(n) = x (n2)
• y(n) = n2x(n)

Which condition determines the causality of the LTI system in terms of its impulse response ?

• Only if the value of an impulse response is zero for all negative values of time
• Only if the value of an impulse response is unity for all negative values of time
• Only if the value of an impulse response is infinity for all negative values of time
• Only if the value of an impulse response is negative for all negative values of time

Check whether the following system is Causal or not? y(t)=x(t) sint5t

• causal

• non causal

• can't ne determined

Check whether the given system is static or dynamic? y(t)=3 x(t)+5

• Static

• Dynamic

• can't be determined

A time invariant system is a system whose output

• increases with a delay in input

• decreases with a delay in input

• remains same with a delay in input

• vanishes with a delay in input

Which among the following are the stable discrete time systems?

1.y(n) = x(4n)

2. y(n) = x(-n)

3. y(n) = ax(n) + 8

4. y(n) = cos x(n)

• 1 & 3

• 2 & 4

• 1, 3 & 4

• 1, 2, 3 & 4

Which one of these is a dynamic system?

• y(n) = x(n) +x(n - 1) + x(n + 1)

• y(n) = x(n) + x(n - 1)

• y(n) = x(n)

• none of these