Find gain in decibels of amplifier has straight voltage gain

Question

Question 1. Which of the following would be used for the highest temperature measurements ?

• Thermistor
• Thermocouple
• IC temperature sensor
• RTD

Question 2. Suppose a liquid level ranging from 5.5 to 8.6 m is linearly converted to pneumatic pressure ranging from 3 to 15 psi. What pressure will result from a level of 7.2 m ?

• 9.94 psi
• 9.55 psi
• 9.60 psi
• 9.58 psi

Question 3.Given a platinum RTD with a temperature coefficient of 0.00392 and an original resistance of 150 Ω at 0°C, find the resistance at 75°C.

• 159.6 Ω
• 182.7 Ω
• 114.3 Ω
• 194.1 Ω

Question 4. An open-loop control system has all the following except?

• actuator
• controller
• sensor
• process

Question 5. The controlled variable in a closed-loop system is the direction of a robot arm. Initially it is at 10o; then it is commanded to go to 35o. What is the set point?

• 35o
• 10o
• 25o
• 50o

Question 6. Which of the following is a closed-loop system?

• Turning on the lights in a house at 6 p.m., and turning them off at 6 a.m.
• Turning the heater off when the temperature reaches 68o or above.
• Pumping water out of the ground.
• Setting the alarm to 8 a.m.

Question 7. Find the current in a ground loop that is 250 m long, has a wire resistance of 0.04 ohms/m, and has a difference of 5 V between grounds.

• 0.500
• 0.578
• 0.673
• 0.558

Question 8. Find the gain in decibels of an amplifier that has a straight voltage gain of 7000.

• 71.8
• 74.2
• 75.3
• 76.9

Question 9. Find the total voltage drop in 200, #20 twisted pair wire circuit carrying 100 mA. The wire has a resistance of 10.15 Ohms per 1000 ft of wire. (Hint: the signal has to go out 200 ft and back)

• 1.6 V
• 0.6 V
• 0.4 V
• 1.3 V

Question 10. A proportional controller for a rotating antenna has a gain Kp of 5 in-oz/deg. The antenna was initially pointing due south, but was then commanded to point southeast. Find the initial torque supplied to the antenna.

• 271 in-oz
• 229 in-oz
• 227 in-oz
• 225 in-oz

Question 11.A proportional control system is to be used to control the wing flap of a jet airplane. The wind load is expected to cause as much as 600 in-lb of torque. The system should be able to keep the flaps with 5o of the set point. Find the gain Kp necessary to meet these requirements.

• 300 in-lbs
• 240 in-lbs
• 120 in-lbs
• 60 in-lbs