1. For a tachometer, if θ(t) is the rotor displacement, e(t) is the output voltage and K is the tachometer constant, then the transfer function is defined as

1. Ks²
2. K/s
3. Ks
4. K

2. A tachometer is added to a servo-mechanism because

1. it is easily adjustable.
2. it can adjust damping
3. it converts velocity of the shaft to a proportional d.c. voltage.
4. it reduces steady-state error.

3. For a tachometer if θ(t) is the rotor displacement, e(t) is the output voltage and K_t is the tachometer constant, then the transfer function is defined as

1. K_ts²
2. K_ts
3. K_t/s
4. K_t

4. The effect of tachometer feedback in a control system is to reduce

1. only time constant
2. only gain
3. damping ratio
4. both gain and time constant

5. In a speed control system, output rate feedback is used to

1. Limit the speed of motor
2. Limit the acceleration of the motor
3. Reduce the damping of the system
4. Increase the gain margin

6. In position control systems, the device used for providing rate feedback is called

1. servomotor
2. tachogenerator
3. synchro
4. potentiometer