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Unit 9: Study of Actuators - Practice Quiz

ECE245 — Elements Of Robotics Laboratory 60 Questions
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1 What is the primary function of an actuator in a robotic system?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. To measure ambient light
B. To store program instructions
C. To produce mechanical motion
D. To transmit sensor data

2 Which working medium is commonly used in a pneumatic cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Hydraulic oil
B. Cooling water
C. Compressed air
D. Electric current

3 Which working medium is commonly used in a hydraulic cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Compressed nitrogen
B. Electrical charge
C. Hydraulic oil
D. Atmospheric air

4 How many fluid-pressure ports does a basic single-acting cylinder usually have?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Two ports
B. Four ports
C. One port
D. Three ports

5 How many working ports does a basic double-acting cylinder usually have?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. One working port
B. Three working ports
C. Four working ports
D. Two working ports

6 What commonly returns the piston of a single-acting cylinder after pressure is removed?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. A light sensor
B. A return spring
C. A rotary gear
D. A second motor

7 In a double-acting cylinder, how is the piston moved in both directions?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. By a spring applied alternately
B. By pressure applied alternately
C. By heat applied continuously
D. By gravity applied continuously

8 What is the outward movement of a cylinder's piston rod called?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Retraction
B. Oscillation
C. Rotation
D. Extension

9 What is the inward movement of a cylinder's piston rod called?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Retraction
B. Revolution
C. Extension
D. Expansion

10 Which component inside a fluid-power cylinder moves because of pressure?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Controller
B. Compressor
C. Reservoir
D. Piston

11 Which cylinder component transfers piston motion to an external robotic mechanism?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Oil tank
B. Pressure gauge
C. Air filter
D. Piston rod

12 Which device directs compressed air or hydraulic fluid to the required cylinder port?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Directional control valve
B. Electrical limit switch
C. Structural mounting bracket
D. Mechanical return spring

13 Which device supplies compressed air to a pneumatic actuator setup?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Air compressor
B. Electric encoder
C. Hydraulic pump
D. Oil reservoir

14 Which device creates fluid flow in a hydraulic actuator setup?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Position sensor
B. Air compressor
C. Return spring
D. Hydraulic pump

15 Compared with pneumatic systems of similar size, hydraulic systems generally provide what advantage?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Greater output force
B. Simpler air exhaust
C. Lower fluid pressure
D. Lighter oil storage

16 Which characteristic is commonly associated with pneumatic actuators?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Perfectly rigid positioning
B. Fast linear motion
C. Very high oil pressure
D. Silent fluid pumping

17 What type of motion is directly produced by a standard piston cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Linear motion
B. Vibratory motion
C. Orbital motion
D. Rotary motion

18 During the NINO V2 actuator study, what should be checked before operating a pneumatic or hydraulic cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. Robot paint is dry
B. Display brightness is high
C. Connections are secure
D. Speaker volume is low

19 Why should hands be kept away from the moving cylinder rod and linked parts during the NINO V2 experiment?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. To reduce oil temperature
B. To increase piston speed
C. To improve air pressure
D. To avoid pinch injuries

20 What is observed when pressure is switched from one port to the other in a double-acting cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Easy
A. The rod begins rotating
B. The cylinder becomes single-acting
C. The motion direction reverses
D. The piston remains fixed

21 During an experiment with NINO V2, compressed air is supplied to one port of a pneumatic cylinder, while extension is opposed by an internal spring. What type of actuator is being tested?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Hydraulic single-acting cylinder
B. Pneumatic single-acting cylinder
C. Pneumatic double-acting cylinder
D. Hydraulic double-acting cylinder

22 A double-acting pneumatic cylinder on NINO V2 must retract. Which valve action will produce the required motion?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Pressurize the rod-end port and exhaust the cap-end port
B. Pressurize the cap-end port and close the rod-end port
C. Close both ports and reduce the supply pressure
D. Exhaust both ports and increase the spring preload

23 A hydraulic cylinder has a piston diameter of and receives a pressure of at its cap end. Ignoring losses, what is its approximate extension force?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A.
B.
C.
D.

24 For the same supply pressure, why is the retraction force of a double-acting cylinder usually lower than its extension force?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The return port always receives a lower pressure
B. The piston seal acts only during cylinder extension
C. The fluid density decreases during cylinder retraction
D. The piston rod reduces the effective retraction area

25 While lifting a nearly constant load with NINO V2, a pneumatic cylinder shows more position variation than a hydraulic cylinder. What best explains this observation?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Air compressibility causes greater position compliance
B. Oil compressibility makes the hydraulic piston rigid
C. Air viscosity prevents pressure from reaching the piston
D. Oil density eliminates all mechanical clearances

26 A pneumatic cylinder on NINO V2 extends too rapidly and strikes its end stop. Which adjustment is most appropriate for reducing its extension speed?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Increase the supply pressure with the regulator
B. Increase the piston diameter without changing flow
C. Block the exhaust port with a shutoff valve
D. Restrict the exhaust flow with a meter-out valve

27 During a hydraulic-cylinder test, the piston motion is jerky and the fluid appears foamy. What is the most likely cause?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The cylinder bore is larger than required
B. Air has entered the hydraulic circuit
C. The reservoir contains too much clean oil
D. The relief valve setting is slightly reduced

28 Which observation best distinguishes a double-acting cylinder from a single-acting cylinder during the NINO V2 laboratory study?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Gravity provides the force throughout both strokes
B. Powered motion occurs only during the extension stroke
C. A mechanical spring controls both directions of motion
D. Powered motion occurs in both extension and retraction

29 A single-acting cylinder extends correctly but fails to retract fully after the pressure is removed. Which fault is most likely?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The piston area is larger than the rod area
B. The supply regulator is set slightly higher
C. The return spring is weak or damaged
D. The directional valve has two working ports

30 A cylinder has a piston diameter of , a rod diameter of , and a rod-end pressure of . Ignoring losses, what is the approximate retraction force?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A.
B.
C.
D.

31 A pneumatic cylinder produces insufficient force to move a NINO V2 joint, although the directional valve switches correctly. Which check should be performed first?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Increase the exhaust tubing length substantially
B. Reverse the polarity of the valve connections
C. Measure the cylinder supply pressure under load
D. Replace the cylinder with a shorter piston rod

32 Why should the hydraulic relief valve be correctly adjusted before operating a cylinder connected to NINO V2?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. It limits maximum pressure and prevents overload
B. It fixes the cylinder speed at a constant value
C. It reverses the cylinder whenever motion is blocked
D. It removes all air bubbles from the hydraulic fluid

33 A hydraulic cylinder continues extending slowly after its directional valve is placed in the neutral position. There is no visible external leakage. What is the most likely explanation?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The reservoir pressure has fallen below atmosphere
B. The piston area has changed during the extension
C. The hydraulic fluid density has increased suddenly
D. Internal leakage is occurring across a seal or valve

34 A cylinder with a piston diameter of receives a flow rate of . Ignoring leakage, what is its approximate extension speed?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A.
B.
C.
D.

35 When comparing equal-sized pneumatic and hydraulic cylinders for a compact high-force movement on NINO V2, why is the hydraulic cylinder generally preferred?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Hydraulic systems commonly operate at higher pressures
B. Hydraulic cylinders require no directional control valve
C. Hydraulic oil expands more readily than compressed air
D. Hydraulic pressure acts only on the piston rod

36 In a double-acting cylinder test, both working ports are blocked while the piston is stationary. What behavior is expected under an external load, assuming negligible leakage?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The piston retracts because both chambers exhaust
B. The piston extends continuously at maximum speed
C. The piston remains hydraulically or pneumatically locked
D. The piston oscillates between both end positions

37 During repeated pneumatic extension tests, the cylinder moves normally without a load but slows greatly when connected to a NINO V2 limb. What is the best interpretation?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. The available pressure-force margin is insufficient
B. The directional valve is converting air into oil
C. The exhaust silencer is raising the piston area
D. The return spring is increasing the supply flow rate

38 Which change will increase cylinder speed while keeping the piston diameter and load unchanged?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Increase the fluid flow rate to the cylinder
B. Add a restriction to the cylinder supply line
C. Decrease the relief pressure below the load pressure
D. Increase the rod diameter without changing flow

39 Before disconnecting a pneumatic or hydraulic cylinder from the NINO V2 test setup, what is the most appropriate safety action?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Move the cylinder rapidly to its full extension
B. Isolate the supply and release stored pressure
C. Increase the regulator setting to stabilize the piston
D. Close only the return line while leaving supply active

40 A double-acting cylinder extends more slowly than it retracts when the same flow rate is supplied during each stroke. What is the main reason?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2 Medium
A. Extension uses the larger full-piston area
B. Retraction eliminates friction at the piston seal
C. Extension uses the smaller annular piston area
D. Retraction always receives a higher supply pressure

41 During a NINO V2 elbow experiment, a single-acting pneumatic cylinder extends when supply pressure is applied and returns when the valve is released. Which explanation best accounts for the return motion?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The return stroke is produced by an internal spring or external load.
B. The return stroke is produced by opening both cylinder ports.
C. The return stroke is produced by increasing the supply pressure.
D. The return stroke is produced by reversing the pump displacement.

42 A double-acting cylinder on NINO V2 moves correctly in extension but stalls during retraction although the pump pressure remains normal. Which fault most directly explains this asymmetric behavior?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The pressure gauge is mounted near the reservoir.
B. The cylinder bore is slightly larger than specified.
C. A restriction exists in the retraction flow path.
D. The supply hose has a uniform internal diameter.

43 For a hydraulic double-acting cylinder, the cap-end area is , the rod-end effective area is , and the pressure is . Neglecting losses, what are the extension and retraction forces?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. extension and retraction
B. extension and retraction
C. extension and retraction
D. extension and retraction

44 NINO V2 shows a compliant, spring-like motion when a pneumatic cylinder supports a limb. Which property most strongly causes this behavior compared with an equivalent hydraulic actuator?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The valve spool always moves at a slower speed.
B. Compressibility of the working air stores elastic energy.
C. The cylinder rod has a lower tensile strength.
D. The pneumatic bore automatically changes its diameter.

45 A single-acting cylinder is used to lift a NINO V2 joint against gravity. The actuator retracts unexpectedly when the control valve is centered. Which design change directly prevents loss of position if the holding requirement exceeds the spring capability?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Increase the exhaust silencer size without changing the valve.
B. Reduce the cylinder stroke while keeping the same spring.
C. Use a double-acting cylinder with a suitable load-holding valve.
D. Replace the hydraulic fluid with a lower-viscosity fluid.

46 A hydraulic cylinder on NINO V2 extends at nearly constant speed even though the load varies during the motion. Which control arrangement most plausibly produces this result?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. A check valve converts cylinder pressure into constant position.
B. A larger reservoir eliminates all changes in actuator velocity.
C. A metering valve regulates flow into or out of the cylinder.
D. A pressure relief valve fixes the cylinder displacement directly.

47 During a pneumatic double-acting cylinder test, the piston moves rapidly at first and then slows near the end of the stroke. The supply pressure is unchanged. Which cause is most likely?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The compressor automatically reverses its delivery direction.
B. The piston area increases near the end of the stroke.
C. End-of-stroke cushioning restricts exhaust flow near the cap.
D. The rod becomes hydraulically locked by the air supply.

48 For the same cylinder bore and pressure, why is the retraction force of a rod-equipped double-acting cylinder lower than its extension force?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The piston seal cancels pressure on the rod side.
B. The rod occupies area on the retraction pressure surface.
C. The return valve removes pressure from both cylinder chambers.
D. The rod increases the pressure acting on the cap end.

49 A hydraulic actuator on NINO V2 exhibits jerky motion only at very low commanded speeds. Which explanation is most consistent with this observation?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The rod area becomes equal to the bore area during retraction.
B. The fluid becomes perfectly incompressible at low speed.
C. The cylinder force becomes independent of pressure at low speed.
D. Static friction alternately holds and releases the piston.

50 A NINO V2 pneumatic joint fails to reach its commanded position under load, while the unloaded cylinder reaches full stroke. Which first diagnostic measurement is most informative?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Measure the ambient temperature without recording actuator state.
B. Measure pressure at the actuator during the loaded motion.
C. Measure the rod diameter only after disconnecting the valve.
D. Measure the reservoir color after the unloaded motion.

51 When switching a hydraulic double-acting cylinder from extension to retraction, NINO V2 produces a sharp impact. Which modification most directly reduces the transient?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Shorten the rod while preserving the same switching sequence.
B. Increase the pressure setting without changing valve timing.
C. Use controlled valve ramping or adjustable flow restriction.
D. Replace the cylinder with a single-acting unit of equal bore.

52 A pneumatic single-acting cylinder and a hydraulic single-acting cylinder have equal bore area and operate at equal pressure. Which statement about ideal powered-stroke force is correct?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The pneumatic cylinder always produces twice the force.
B. The hydraulic cylinder produces force only during retraction.
C. Their ideal force is equal because for both fluids.
D. Their force cannot be compared without knowing the stroke length.

53 A cylinder has a piston area of and a stroke of . Ignoring dead volume and leakage, how much fluid volume is required for one full powered stroke?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A.
B.
C.
D.

54 A hydraulic cylinder on NINO V2 slowly drifts while both directional controls appear centered. Which evidence most strongly indicates internal piston-seal leakage rather than external hose leakage?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The reservoir level drops rapidly during every cycle.
B. Fluid appears around the cylinder mounting bracket.
C. The supply hose visibly separates from its connector.
D. The rod moves with no visible fluid at fittings or hoses.

55 Why is a hydraulic actuator generally preferred over a pneumatic actuator for holding a heavy NINO V2 limb at a precise intermediate position?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Hydraulic actuators always consume less energy at every load.
B. Hydraulic cylinders require no valve to control intermediate positions.
C. Hydraulic fluid is less compressible and supports greater force density.
D. Pneumatic cylinders cannot generate force during any powered stroke.

56 An experimenter reverses the ports of a double-acting cylinder without changing the valve command labels. What change should be expected during the test?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The cylinder stroke doubles because both chambers are pressurized.
B. The piston force becomes zero in both directions.
C. The commanded extension and retraction directions are interchanged.
D. The cylinder becomes single-acting without changing its seals.

57 A pneumatic cylinder moves slower when the NINO V2 payload increases, although the regulator maintains the same nominal pressure. Which relation best explains the observation?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Constant pressure guarantees constant speed regardless of external load.
B. Increased load increases the piston area and therefore the stroke length.
C. The load changes a double-acting cylinder into a single-acting cylinder.
D. Increased load reduces net force and can reduce available flow-driven speed.

58 A single-acting cylinder is selected for a joint whose motion must be actively controlled in both directions under changing loads. What is the fundamental limitation of this selection?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. The cylinder must always use hydraulic fluid instead of air.
B. Only one direction receives direct fluid-powered force.
C. The cylinder cannot be connected to a directional valve.
D. The cylinder cannot contain a piston seal or guide.

59 During a hydraulic cylinder experiment, the actuator speed increases after the fluid warms while the pump setting is unchanged. Which mechanism best explains the result?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. Lower viscosity reduces flow resistance through valves and passages.
B. Higher temperature increases the cylinder bore area directly.
C. Thermal expansion increases the piston stroke without moving fluid.
D. Heating converts the hydraulic actuator into a pneumatic actuator.

60 When evaluating a NINO V2 actuator, which test result most clearly distinguishes a double-acting cylinder from a spring-return single-acting cylinder?

Study the action of pneumatic and hydraulic single- and double-acting cylinders using Sierena's humanoid robot NINO V2. Hard
A. It changes speed when the external joint load is changed.
B. It reaches one end position when pressure is applied to one port.
C. It produces controlled force in both stroke directions under valve actuation.
D. It returns after supply pressure is removed from the working port.
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