Title: Module 3 Test
Course: WIND 100WH Introduction to Wind Energy > Section: WIND 100WH Introduction to Wind Energy

Q: A HAWT uses various sensors as inputs to the PLC. The PLC relies on internal _________________ to define the actions taken by the sensor data.
- programming
- memory
- mechanics
- cooling
A: programming

Q: On a HAWT, the generator is connected to the gearbox’s output shaft. This shaft is called a/n ___________.
- low-speed shaft
- high-speed shaft
- high-speed coupling
- low-speed coupling
A: high-speed shaft

Q: The fewer blades a HAWT has, the ___________ they have to spin to produces the same amount of power.
- slower
- faster
- less smoothly
- more evenly
A: faster

Q: A blade is considered _____________ when positioned at the zero point.
- pitch control
- stalled
- feathered
- wind facing
A: feathered

Q: The position, in degrees, of the turbine blade’s axis is called the _____________.
- feather stall
- blade pitch
- zero pitch
- right angle pitch
A: blade pitch

Q: A commercial wind turbine has blades 120 feet in length from the center of the hub to the tips. If the turbine is turning at 20 rpm, what is the angular speed of the blade tips?
- 35.6 rpm, or 220 miles
- 1,750.78 ft/s, or 10 feet per mile an hour
- 251.3 feet per second, or 171.4 mph
- 171.4 mph, or 220 feet per hour
A: 251.3 feet per second, or 171.4 mph

Q: If you were to feather the blades to make them stall at higher speeds, you’d be ______________.
- =increasing their angular velocity
- decreasing their inefficiency
- accelerating the rotor
- unloading them and slowing their rotational speed
A: unloading them and slowing their rotational speed

Q: Yaw control systems mostly use a/n ________________, a gear reduction box, and a yaw ring gear.
- hydraulic system
- electric motor
- PLC hub system
- reluctance device
A: electric motor

Q: What device/sensor acts as an input to the PLC in order for it to tell the yaw motors what direction to turn?
- The CPU
- The invertor
- The anemometer
- The thermometer
A: The anemometer

Q: On larger wind turbines, what device is responsible for limiting the number of times the nacelle can rotate in one direction?
- Yaw counter
- PLC
- Inverter
- Anemometer
A: PLC

Q: Brakes are utilized on most large wind turbines to stop the rotor and the lock _____________.
- the yaw motor
- the yaw ring
- the tower assembly
- the pitch rotor
A: the yaw ring

Q: What’s it called when information is gathered and archived for maintenance issues?
- SCADA
- Ethernet acquisition
- Data return
- Data acquisition
A: Data acquisition

Q: An anemometer outputs wind speeds by utilizing _______________.
- an ultrasonic system
- a small rotor connected to rotary encoders
- DC voltage generation
- any of the above is correct
A: any of the above is correct

Q: Anemometers generate a _______________ to indicate wind speed, while wind vanes utilize variable resistors and indicate wind direction by _______________.
- voltage / resistance
- sine wave / power signals
- voltage / pulsing data signals
- tor / encoders
A: voltage / resistance

Q: The yaw drive system pivots the _____________ at the top of the tower.
- nacelle
- rotor
- blades
- linkages
A: nacelle

Q: A PLC is a programmable computer system that controls the actions of other devices based on data from _________.
- turn-on devices
- sensing devices
- system modules
- none of the above
A: sensing devices

Q: PLCs are very good in controlling wind turbine subsystems because the information can be easily stored within its ________.
- PIC
- ISU
- EPROM
- DAC
A: EPROM

Q: What type of control is used to transmit information between sensors and output devices in most large wind turbines?
- Digital control
- Analog control
- Discrete control
- Sensor power control
A: Analog control

Q: What type of control is the closed-loop system?
- It is PSV control
- It is logic control
- It is feedback control
- It is forced control
A: It is feedback control

Q: _________________ occurs in a cylinder when fluid enters the top and pushes the piston down.
- Decreased pressure
- Displacement
- Volumetric pressure
- Transfer power
A: Displacement

Q: What’s the name of the pump that gives out a predetermined quantity of fluid per revolution?
- Hydraulic pump
- Low displacement hydraulic pump
- Positive displacement pump
- Negative displacement pump
A: Positive displacement pump

Q: What type of hydraulic pump has slots in the rotor?
- Gear pump
- Lobe pump
- Vane pump
- Arc pump
A: Vane pump

Q: A device that forces fluid to flow in a required direction is called a/n ____________.
- flow device
- variable flow device
- coupled device
- directional control device
A: directional control device

Q: A valve in a hydraulic system that consists of a poppet and is designed to allow flow in one direction (thus preventing backflow) is called a/n ___________.
- lobe valve
- directional valve
- check valve
- ball valve
A: check valve

Q: A directional hydraulic control device that’s mounted in a manifold is called a _______ valve.
- relief
- flow control
- cartridge
- pintle
A: cartridge

Q: On a two-blade wind turbine, the counterweights perform two functions. What are they?
- Increase angular velocity and dampen noise
- Maintain torque and velocity
- Allow wobble in high winds
- Balance the shaft and also harvest the wind
A: Balance the shaft and also harvest the wind

Q: Wind gusts on a large wind turbine puts great stress on three components within the nacelle if not controlled properly?
- Blades, shafts, gearbox
- Yaw brake, generator, tower
- Tower, brakes, yaw motors
- Anemometer, PLC, and wind vanes
A: Blades, shafts, gearbox

Q: What two main components, mounted to the nacelle’s bedplate, are responsible for moving the nacelle into and out of the incoming wind?
- Yaw drive and yaw pitch control motors
- Yaw motor and yaw ring
- Tower top collar and ring motor
- Yaw rotator and gear
A: Yaw motor and yaw ring

Q: What provides the information to the system when measuring a variance in wind direction?
- Flow sensor
- Timer
- Angular sensor
- Directional Sensor
A: Directional Sensor

Q: What are the two different active systems for controlling blade pitch?
- Hydraulic control and electric motor control
- Spring control and counterweight control
- Hydraulic control and pneumatic control
- Pressure control and reduction system control
A: Hydraulic control and electric motor control