1.1.

(a) 0 (b) 1.1

(c) 0.5 (d) 1

1.2. For the waveform V (t) = 2 + cos the ratio V rms / V average is

(a) (b)

(c) p (d)

1.3. A system with transfer function ­ , subjected to a step input takes 10 seconds to reach 50% of the step height. The value of t is

(a) 6.9 s (b) 10 s

(c) 14.4 s (d) 20 s

• Relationship between input x (t) and output y (t) of a system is given as

The transfer function of this system is

(a)

(b)

(c) 1+ s 2e -2s

(d) 1+ s 2e 2s

1.5. A transfer function has two zeroes at infinity. Then the relation between the numerator degree (N) and the denominator degree (M) of the transfer function is,

(a) N=M+2

(b) N=M-2

(c) N=M+1

(d) N=M-l

• The system is subjected to a step input. The system output y (t) as t ® ¥ is

(a) 0.8 (c) -0.4

(b) 0.4 (d) unbounded

1.7. The transfer function betweenY 2 and Y 1 in Fig. 1.7 is

(a) a+b

(b) (a+b)c

(C) ­

(d)

1.8. In control system design, gain and phase margins are usually provided to

(a) account for the uncertainties in the system

(b) make the system respond fast

(c) reduce the overshoot in step response

(d) reduce the steady state offset.

1.9. The lengths of two discrete time sequences X 1 (n) are 5 and 7 respectively. The maximum length of sequence x 1 (n) * x 2(n) is

(a) 5 (b) 6

(c) 7 (d) 11

1.10. The output voltage of the circuit in Fig. 1.10 for t > 0 is

(a)

(b)

(c)

(d)

• In the circuit shown in Fig. 1.11, V i is 4 V. Assuming the diodes to be ideal, V o is
• 3V
• 4V
• 4.5 V
• 6 V

1.12. The input voltage, V 1 is 4 + 3 sin wt. assuming all elements to be ideal, the average of the output voltage V o in Fig. 1.12 is

(a) -3 V (b) +3 V

(c) -7 V (d) +7 V

1.13. In the JFET amplifier circuit shown in Fig. 1.13, the signal outputs V 1 and v 2 are related as

(a)

(b)

(c)

(d)

1.14. The op-amp in the amplifier circuit shown in Fig. 1.14 has an offset voltage of 10 mV and it is ideal otherwise. If V i is zero, the output voltage V o is

• 0
• 10 mV
• 100 mV
• 110 mV

 1.15. A voltmeter connected across the 10 k W resistor in the Fig. 1.15, reads 5 V. The voltmeter is rated at 1000 ohms/volt and has a full scale reading of 10 V. The supply voltage V s in volt is

• 30
• 50
• 55
• 80