1
GATE ECE 2017 Set 1
+1
-0.3
Consider a single input single output discrete-time system with $$h\left[ n \right]\,$$ as input and $$y\left[ n \right]\,$$ as output, where the two are related as
$$y\left[ n \right]\, = \left\{ {\matrix{ {n\left| {x\left[ n \right]} \right|,} & {for\,\,0 \le n \le 10} \cr {x\left[ n \right] - x\left[ {n - 1} \right],} & {otherwise,} \cr } } \right.$$

Which one of the following statements is true about the system?

A
It is causal and stable
B
It is causal but not stable
C
It is not causal but stable
D
It is neither causal nor stable
2
GATE ECE 2011
+1
-0.3
A system is defined by its impulse response $$h\left( n \right) = {2^n}\,u\left( {n - 2} \right).$$ The system is
A
stable and causal.
B
causal but not stable.
C
stable but not causal.
D
unstable and non causal.
3
GATE ECE 2010
+1
-0.3
Two discrete time systems with impulse responses $${h_1}\left[ n \right]\, = \delta \left[ {n - 1} \right]$$ and $${h_2}\left[ n \right]\, = \delta \left[ {n - 2} \right]$$ are connected in cascade. The overall impulse response of the cascaded system is
A
$$\delta \left[ {n - 1} \right] + \delta \left[ {n - 2} \right]$$
B
$$\delta \left[ {n - 4} \right]$$
C
$$\delta \left[ {n - 3} \right]$$
D
$$\delta \left[ {n - 1} \right]\delta \left[ {n - 2} \right]$$
4
GATE ECE 2004
+1
-0.3
The impulse response $$h\left[ n \right]$$ of a linear time-invariant system is given by $$h\left[ n \right]$$ $$= u\left[ {n + 3} \right] + u\left[ {n - 2} \right] - 2\,u\left[ {n - 7} \right],$$ where $$u\left[ n \right]$$ is the unit step sequence. The above system is
A
stable but not causal.
B
stable and causal.
C
causal but unstable.
D
unstable and not causal.
GATE ECE Subjects
Signals and Systems
Network Theory
Control Systems
Digital Circuits
General Aptitude
Electronic Devices and VLSI
Analog Circuits
Engineering Mathematics
Microprocessors
Communications
Electromagnetics
EXAM MAP
Joint Entrance Examination