Question

If a signal f(t) has energy E, the energy of the signal f(2t) is equal to
1. E
2. E/2
3. 2E
4. 4E

Answer 1

Correct Answer - Option 2 : E/2

Concept:

If the energy of signal x(t) is E then

The energy of signal Ax(Bt + c) is \(\frac{{{A}^{2}}E}{\left| B \right|}\)

Calculation:

Comparing with the standard equation

A = 1

B = 2

C = 0

Energy of y(t) \(=\frac{{{A}^{2}}E}{\left| B \right|}\)

\(=\frac{E}{2}\)

Hence, option 2 is correct.