A signal containing only two frequency components (3 kHz and 6 kHz) is sampled at the rate of 8 kHz, and then passed through a low pass filter with a cut-off frequency of 8 kHz. The filter output

A 1 kHz sinusoidal signal is ideally sampled at 1500 samples/sec and the sampled signal is passed through an ideal low-pass filter with cutoff frequency 800 Hz. The output signal has the frequency

A

Zero Hz

B

0.75 kHz

C

0.5 kHz

D

0.25 kHz

Let x(t) = 2cos(800πt) + cos(1400πt).x(t) is sampled with the rectangular pulse train shown in the figure. The only spectral components (in kHz) present in the sampled signal in the frequency range 2.5 kHz to 3.5 kHz are

A

2.7, 3.4

B

3.3, 3.6

C

2.6, 2.7, 3.3, 3.4, 3.6

D

2.7, 3.3

A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t) where
$$g\left( t \right) = \sum\limits_{k = - \infty }^\infty {{{\left( { - 1} \right)}^k}\delta \left( {t - 0.5 \times {{10}^{ - 4}}k} \right)} $$
The resulting signal is then passed through an ideal low pass filter with bandwidth 1 kHz. The output of the low pass filter would be

A

δ(t)

B

m(t)

C

0

D

m(t) δ(t)

A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t). The resulting signal is passed through an ideal low pass filter with bandwidth 1 kHz. The output of the low pass filter would be :

A

Impulse

B

m(t)

C

0

D

m(t)del(t)

A signal x(t) = 100cos(24π × 10³)t is ideally sampled with a sampling period of 50 psec and then passed through an ideal lowpass filter with cutoff frequency of 15 kHz. Which of the following frequencies is/are present at the filter output?

A

12 kHz only

B

8 kHz only

C

12 kHz and 9 kHz

D

12 kHz and 8 kHz

The signal $$\cos \left( {10\pi t + \frac{\pi }{4}} \right)$$ is ideally sampled at a sampling frequency of 15 Hz. The sampled signal is passed through a filter with impulse response $$\left( {\frac{{\sin \left( {\pi t} \right)}}{{\pi \tau }}} \right)\cos \left( {40\pi t - \frac{\pi }{2}} \right).$$ The filter output is

A

$$\frac{{15}}{2}\cos \left( {40\pi t - \frac{\pi }{4}} \right)$$

B

$$\frac{{15}}{2}\left( {\frac{{\sin \left( {\pi t} \right)}}{{\pi t}}} \right)\cos \left( {10\pi t + \frac{\pi }{4}} \right)$$

C

$$\frac{{15}}{2}\cos \left( {10\pi t - \frac{\pi }{4}} \right)$$

D

$$\frac{{15}}{2}\left( {\frac{{\sin \left( {\pi t} \right)}}{{\pi t}}} \right)\cos \left( {10\pi t - \frac{\pi }{2}} \right)$$

The following question is based on the given data for an examination. A. Candidates appeared 10500 B. Passed in all the five subjects 5685 C. Passed in three subjects only 1498 D. Passed in two subjects only 1250 E. Passed in one subject only 835 F. Failed in English only 78 G. Failed in Maths only 275 H. Failed in Physics only 149 I. Failed in Chemistry only 147 J. Failed in Biology only 221 How many candidates passed in at least four subjects ?

A

6555

B

5685

C

1705

D

870

A signal represented by x(t) =5cos 400πt is sampled at a rate 300 samples/sec. The resulting samples are passed through an ideal low pass filter of cut-off frequency 150 Hz. Which of the following will be contained in the output of the LPF?

A

100 Hz

B

100 Hz, 150 Hz

C

50 Hz, 100 Hz

D

50 Hz, 100 Hz, 150 Hz

If the signal to be analyzed is an analog signal, we would pass it through an anti-aliasing filter with B as the bandwidth of the filtered signal and then the signal is sampled at a rate __________

A

Fs ≤ 2B

B

Fs ≤ B

C

Fs ≥ 2B

D

Fs = 2B

The low-pass active filter shown in the figure has a cut-off frequency of 2 kHz and a pass band gain of 1.5. The values of the resistors are

A

R1 = 10 k$$\Omega $$; R2 = 1.3 $$\Omega $$

B

R1 = 30 k$$\Omega $$; R2 = 1.3 $$\Omega $$

C

R1 = 10 k$$\Omega $$; R2 = 1.7 $$\Omega $$

D

R1 = 30 k$$\Omega $$; R2 = 1.7 $$\Omega $$