Identify the signal x(2t - 3) given x(t) as

This question was previously asked in

TANGEDCO AE EC 2015 Official Paper

Option 2 :

ISRO Scientist ECE: 2020 Official Paper

349

80 Questions
240 Marks
90 Mins

__Concept:__

Time-shifting property: When a signal is shifted in the time domain it is said to be delayed or advanced based on whether the signal is shifted to the right or left.

For example:

Time scaling property: A signal is scaled in the time domain with the scaling factor 'a'.

If a > 1, then the signal is contracted by a factor of 'a' along the time axis.

if a < 1, then the signal is expanded by a factor of 'a' along the time axis.

For example:

__Analysis:__

Whenever there is a combination of operations care should be taken while following the sequence of operations.

**Correct approach:**

x[2(t - 1.5)]

First, time scale the signal by factor 2.

Then, time shift the signal by 1.5

**Incorrect approach:**

x[2(t - 1.5)]

First, time shift the signal by 1.5

Then, time scale the signal by 2.

or,

**Correct approach:**

x[2t - 3]

First, time shift the signal by 3.

Then, time scale the signal by 2

**Incorrect approach:**

x[2t - 3]

First, time scale the signal by 2

Then, time shift the signal by 3.