1Which early device is commonly considered an important predecessor of modern robots?
Evolution of robotics
Easy
A.Telegraph machine
B.Printing press
C.Steam engine
D.Mechanical clock
Correct Answer: Mechanical clock
Explanation:
Mechanical clocks used gears and programmed movements, making them early examples of automated machines.
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2The word "robot" was first introduced through a play written by which author?
Evolution of robotics
Easy
A.Alan Turing
B.Isaac Newton
C.Karel Čapek
D.Leonardo da Vinci
Correct Answer: Karel Čapek
Explanation:
Karel Čapek introduced the word "robot" in his 1920 play R.U.R.
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3Which classification describes robots according to their physical structure and joint arrangement?
Classification of robots
Easy
A.Geometric classification
B.Material classification
C.Speed classification
D.Color classification
Correct Answer: Geometric classification
Explanation:
Geometric classification groups robots by their shapes, links, and joint arrangements.
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4A robot that operates mainly in a fixed location is called a:
Classification of robots
Easy
A.Climbing robot
B.Swimming robot
C.Flying robot
D.Stationary robot
Correct Answer: Stationary robot
Explanation:
A stationary robot remains in a fixed place while performing its tasks.
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5Which component provides movement to a robot joint?
Components of a robotic system
Easy
A.Gripper
B.Actuator
C.Sensor
D.Controller
Correct Answer: Actuator
Explanation:
An actuator converts energy into physical movement at a robot joint.
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6What is the main function of a sensor in a robotic system?
Components of a robotic system
Easy
A.Supply structure
B.Store programs
C.Hold objects
D.Detect conditions
Correct Answer: Detect conditions
Explanation:
Sensors detect information such as position, distance, force, or temperature.
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7Which component makes decisions and sends commands to robot actuators?
Components of a robotic system
Easy
A.Link
B.Gripper
C.Battery
D.Controller
Correct Answer: Controller
Explanation:
The controller processes information and sends commands that coordinate robot movement.
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8What does one degree of freedom represent in a robot?
Degrees of freedom (DOF)
Easy
A.One independent motion
B.One power source
C.One attached tool
D.One sensing device
Correct Answer: One independent motion
Explanation:
A degree of freedom represents one independent movement or position variable.
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9How many degrees of freedom does a simple object have when it can move only forward and backward along a straight line?
Degrees of freedom (DOF)
Easy
A.Two
B.Six
C.One
D.Three
Correct Answer: One
Explanation:
Movement along one independent straight-line direction requires one degree of freedom.
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10Which type of motion turns a robot link around an axis?
Degrees of freedom (DOF)
Easy
A.Thermal motion
B.Rotational motion
C.Vibrational motion
D.Linear motion
Correct Answer: Rotational motion
Explanation:
Rotational motion changes the angle of a link around an axis.
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11Which coordinate system uses perpendicular axes such as , , and ?
Robot coordinate systems
Easy
A.Spherical system
B.Joint system
C.Cartesian system
D.Cylindrical system
Correct Answer: Cartesian system
Explanation:
A Cartesian coordinate system describes position using perpendicular , , and axes.
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12In a robot coordinate system, what does the -axis usually represent?
Robot coordinate systems
Easy
A.A tool weight
B.A joint material
C.A spatial direction
D.A motor voltage
Correct Answer: A spatial direction
Explanation:
The -axis is one of the spatial reference directions used to describe robot position.
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13What is the workspace of a robot?
Robot workspace
Easy
A.Power supply
B.Control program
C.Reachable region
D.Tool attachment
Correct Answer: Reachable region
Explanation:
A robot's workspace is the region that its end-effector can reach.
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14Which factor directly affects the size of a robot's workspace?
Robot workspace
Easy
A.Arm link lengths
B.Paint color
C.Warning label
D.Brand name
Correct Answer: Arm link lengths
Explanation:
The lengths of the robot's links help determine how far its end-effector can reach.
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15What is the end-effector of a robot?
Robot anatomy
Easy
A.Base cover
B.Power cable
C.Main controller
D.Task tool
Correct Answer: Task tool
Explanation:
The end-effector is the device attached to the robot arm for performing a task.
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16What is the main purpose of a robot link?
Robot anatomy
Easy
A.Measure temperature
B.Store software
C.Generate instructions
D.Connect joints
Correct Answer: Connect joints
Explanation:
Links are rigid parts that connect the joints of a robot manipulator.
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17Which manipulator uses three mutually perpendicular linear motions?
Types of robotic manipulators
Easy
A.Polar manipulator
B.Cartesian manipulator
C.SCARA manipulator
D.Articulated manipulator
Correct Answer: Cartesian manipulator
Explanation:
A Cartesian manipulator moves along three perpendicular linear axes.
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18Which manipulator commonly has several rotary joints similar to a human arm?
Types of robotic manipulators
Easy
A.Delta manipulator
B.Cylindrical manipulator
C.Cartesian manipulator
D.Articulated manipulator
Correct Answer: Articulated manipulator
Explanation:
An articulated manipulator uses rotary joints and has an arm-like structure.
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19What makes a mobile robot different from a stationary robot?
Mobile robots
Easy
A.It uses no sensors
B.It cannot use power
C.It can change location
D.It has no controller
Correct Answer: It can change location
Explanation:
A mobile robot can move from one location to another using wheels, tracks, legs, or other mechanisms.
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20Which robot is most commonly used for repetitive welding in a factory?
Industrial and service robots
Easy
A.Domestic robot
B.Educational robot
C.Entertainment robot
D.Industrial robot
Correct Answer: Industrial robot
Explanation:
Industrial robots are designed for repetitive manufacturing tasks such as welding, painting, and assembly.
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21Which development most directly enabled modern industrial robots to perform repeatable tasks with improved accuracy?
Evolution of robotics
Medium
A.Programmable digital controllers
B.Mechanical springs for energy storage
C.Larger manual control panels
D.Fixed decorative machine frames
Correct Answer: Programmable digital controllers
Explanation:
Programmable digital controllers allow robot motions and task sequences to be stored, modified, and executed repeatedly with precise timing.
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22A factory replaces a fixed automation machine with a programmable robot because product models change frequently. Which historical trend does this illustrate?
Evolution of robotics
Medium
A.Movement from rigid automation to flexible automation
B.Movement from electric drives to manual drives
C.Movement from programmable systems to mechanical systems
D.Movement from feedback control to open-loop control
Correct Answer: Movement from rigid automation to flexible automation
Explanation:
Programmable robots can be reconfigured for different products, which is a key advantage of flexible automation over dedicated machinery.
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23A robot is selected for assembly because it moves vertically along a column and rotates around the column while maintaining a cylindrical work envelope. How is it classified by configuration?
Classification of robots
Medium
A.Cylindrical robot
B.Cartesian robot
C.Delta robot
D.Spherical robot
Correct Answer: Cylindrical robot
Explanation:
A cylindrical robot typically combines a rotary base motion with linear motions, producing a cylindrical workspace.
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24A robot has three mutually perpendicular linear axes and is used to move parts precisely within a rectangular volume. Which classification best matches it?
Classification of robots
Medium
A.Cartesian robot
B.Articulated robot
C.Polar robot
D.SCARA robot
Correct Answer: Cartesian robot
Explanation:
Cartesian robots use three linear axes, commonly labeled X, Y, and Z, and create a rectangular or box-shaped workspace.
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25A robot arm repeatedly misses its target because its controller does not receive accurate joint-angle measurements. Which component is most likely faulty?
Components of a robotic system
Medium
A.Protective enclosure
B.Position sensor
C.End effector
D.Manipulator link
Correct Answer: Position sensor
Explanation:
Position sensors measure joint or axis displacement and provide feedback needed for accurate closed-loop motion control.
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26Which component converts commands from the controller into physical movement at a robot joint?
Components of a robotic system
Medium
A.Encoder
B.Actuator
C.Teach pendant
D.Workholding fixture
Correct Answer: Actuator
Explanation:
An actuator produces mechanical motion from an electrical, hydraulic, or pneumatic command.
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27A rigid object in three-dimensional space generally requires how many independent motions to specify its complete position and orientation?
Degrees of freedom (DOF)
Medium
A.Five degrees of freedom
B.Four degrees of freedom
C.Six degrees of freedom
D.Three degrees of freedom
Correct Answer: Six degrees of freedom
Explanation:
A rigid body has three translational motions and three rotational motions, giving a total of six degrees of freedom.
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28A robot can translate along X, Y, and Z and rotate about the Z-axis, but it cannot independently control rotation about X or Y. What is its effective DOF?
Degrees of freedom (DOF)
Medium
A.Three
B.Six
C.Four
D.Two
Correct Answer: Four
Explanation:
The robot independently controls three translations and one rotation, so its effective degree of freedom is four.
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29A robot programmer wants to describe a point relative to the robot base rather than relative to the tool. Which coordinate system is most appropriate?
Robot coordinate systems
Medium
A.World or base coordinate system
B.Gripper coordinate system
C.Joint coordinate system
D.Tool coordinate system
Correct Answer: World or base coordinate system
Explanation:
The world or base coordinate system expresses positions with respect to a fixed reference associated with the robot or workcell.
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30In joint coordinates, a robot motion command primarily specifies:
Robot coordinate systems
Medium
A.The color and size of the workpiece
B.The Cartesian position of the tool center point
C.The speed of the conveyor alone
D.The desired angle or displacement of each joint
Correct Answer: The desired angle or displacement of each joint
Explanation:
Joint coordinates define robot motion using the individual variables of each joint, such as angle for a revolute joint or distance for a prismatic joint.
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31A robot's reachable workspace includes locations its tool can reach, but the tool cannot achieve the required orientation at some of them. What does this indicate?
Robot workspace
Medium
A.The robot has no reachable workspace
B.The robot is operating only in joint coordinates
C.The robot has reachability but limited dexterity
D.The robot has unlimited positioning accuracy
Correct Answer: The robot has reachability but limited dexterity
Explanation:
Reachability concerns whether a point can be reached, while dexterity concerns the range of orientations achievable at that point.
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32A revolute robot joint is mechanically restricted to rotate between and . What is the most direct effect of this restriction?
Robot workspace
Medium
A.It removes some regions from the workspace
B.It eliminates the need for feedback
C.It changes the robot into a mobile robot
D.It expands the robot's workspace
Correct Answer: It removes some regions from the workspace
Explanation:
Joint limits restrict allowable configurations, so some positions or orientations that are geometrically possible become inaccessible.
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33In a robotic arm, which part is primarily responsible for connecting adjacent joints and transmitting loads between them?
Robot anatomy
Medium
A.End-effector pad
B.Sensor
C.Link
D.Controller
Correct Answer: Link
Explanation:
Links are rigid structural members that connect joints and transfer forces and motion through the manipulator.
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34A welding robot needs to change the angle of its welding torch without significantly changing the torch location. Which anatomical feature provides this capability?
Robot anatomy
Medium
A.A larger controller cabinet
B.An additional wrist joint
C.A stationary safety fence
D.A longer conveyor belt
Correct Answer: An additional wrist joint
Explanation:
Wrist joints provide orientation changes near the end of the arm, allowing the tool angle to change while its position remains nearly fixed.
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35Which manipulator is generally well suited for high-speed pick-and-place operations because of its lightweight parallel-link structure?
Types of robotic manipulators
Medium
A.Delta manipulator
B.Cartesian manipulator
C.Single-axis manipulator
D.Cylindrical manipulator
Correct Answer: Delta manipulator
Explanation:
Delta manipulators use parallel arms and a lightweight moving platform, enabling high acceleration and rapid pick-and-place motion.
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36A manufacturer needs a robot for inserting components that offers selective compliance in the horizontal plane while remaining rigid vertically. Which type is most appropriate?
Types of robotic manipulators
Medium
A.Tracked mobile robot
B.Cartesian gantry
C.Spherical manipulator
D.SCARA manipulator
Correct Answer: SCARA manipulator
Explanation:
SCARA robots are designed for assembly and insertion tasks, with horizontal compliance and strong vertical rigidity.
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37A warehouse robot must turn in place and move efficiently on a smooth floor. Which drive arrangement is most suitable?
Mobile robots
Medium
A.Single rigid caster
B.Fixed four-wheel steering
C.Differential drive
D.Vertical linear drive
Correct Answer: Differential drive
Explanation:
A differential-drive robot can turn by varying the speeds of its left and right wheels, including rotating about a point between the wheels.
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38A mobile robot uses cameras and range sensors to build a map while estimating its own changing position. Which capability is it demonstrating?
Mobile robots
Medium
A.Open-loop actuation
B.Fixed-point calibration
C.Purely mechanical transmission
D.Simultaneous localization and mapping
Correct Answer: Simultaneous localization and mapping
Explanation:
Simultaneous localization and mapping, or SLAM, combines estimation of the robot's position with construction or refinement of an environment map.
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39A robot loads parts into a machine inside a controlled factory cell, repeating the same motion throughout a shift. Which category best describes it?
Industrial and service robots
Medium
A.Domestic service robot
B.Industrial robot
C.Entertainment robot
D.Personal mobility robot
Correct Answer: Industrial robot
Explanation:
Industrial robots perform structured manufacturing tasks such as machine loading, welding, assembly, and material handling.
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40A hospital robot delivers medicines through corridors shared with patients and staff. Which design priority is especially important for this application?
Industrial and service robots
Medium
A.Permanent fixation to the floor
B.Maximum joint stiffness only
C.Safe human-robot interaction
D.Operation without any sensors
Correct Answer: Safe human-robot interaction
Explanation:
Service robots operating around people require sensing, collision avoidance, appropriate speed control, and behaviors that support safe interaction.
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41A manufacturing system changes from fixed-sequence automation to robots equipped with force sensing, vision, and adaptive control. Which capability most directly represents the major evolutionary transition involved?
Evolution of robotics
Hard
A.Moving from programmable repetition toward environment-aware autonomy
B.Replacing hydraulic actuators with electric motors
C.Replacing all human operators with mobile platforms
D.Increasing the number of joints in every manipulator
Correct Answer: Moving from programmable repetition toward environment-aware autonomy
Explanation:
The key transition is from repeating predefined motions to perceiving conditions and adapting behavior through sensing and intelligent control.
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42An early industrial robot repeats a stored trajectory accurately, but it cannot compensate when a part is displaced by 8 mm. Which development would most fundamentally address this limitation?
Evolution of robotics
Hard
A.A larger gearbox with a higher reduction ratio
B.A heavier base with increased structural stiffness
C.A faster teach pendant with more stored points
D.Closed-loop sensing combined with feedback control
Correct Answer: Closed-loop sensing combined with feedback control
Explanation:
Feedback from vision, force, or position sensors allows the robot to detect displacement and modify its trajectory instead of replaying a fixed path.
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43A robot has fixed mounting, programmable motion, six revolute joints, and a gripper used for welding vehicle frames. Which classification is most specific?
The robot is fixed, used in manufacturing, and has a serial chain of revolute joints, which identifies it as an articulated industrial manipulator.
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44A robot transports components through a warehouse, determines routes using lidar, and changes its destination when aisles are blocked. Which classification best captures its primary operating behavior?
Classification of robots
Hard
A.Fixed-sequence manipulator
B.Point-to-point gantry robot
C.Teleoperated articulated robot
D.Autonomous mobile robot
Correct Answer: Autonomous mobile robot
Explanation:
It moves through the environment, perceives obstacles, and plans route changes without continuous human control.
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45A robot reaches commanded positions accurately when unloaded but develops large errors while lifting variable payloads. Which subsystem interaction should be investigated first?
Components of a robotic system
Hard
A.Controller timing and operator interface
B.Workspace boundaries and emergency-stop wiring
C.Actuator sizing, transmission compliance, and feedback
D.End-effector color and tool labeling
Correct Answer: Actuator sizing, transmission compliance, and feedback
Explanation:
Payload-dependent errors commonly result from insufficient actuator torque, elastic transmission effects, or feedback limitations under load.
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46A vision-guided pick-and-place robot consistently grasps objects 40 mm to the left of their actual locations, although joint encoders report correct positions. Which component-level fault is most likely?
Components of a robotic system
Hard
A.Excessive motor torque in the wrist actuator
B.Incorrect calibration between camera and robot frames
C.Incorrect emergency-stop circuit configuration
D.Insufficient payload rating of the gripper
Correct Answer: Incorrect calibration between camera and robot frames
Explanation:
A consistent spatial offset between sensed object coordinates and robot motion indicates an error in the transformation linking the camera and robot coordinate systems.
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47A rigid object in three-dimensional space requires independent control of three translations and three rotations. A robot can control only three translations and rotation about the vertical axis. What is the primary limitation?
Degrees of freedom (DOF)
Hard
A.It has redundant control for every planar task
B.It necessarily has a singularity at every position
C.It has insufficient control for arbitrary six-dimensional pose
D.It cannot reach any point outside its base frame
Correct Answer: It has insufficient control for arbitrary six-dimensional pose
Explanation:
Arbitrary rigid-body pose requires six independent DOF. The robot provides only four, so some orientations cannot be independently controlled.
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48A planar serial robot has two revolute joints, but its task requires positioning a tool at while maintaining a specified tool orientation in the plane. What is the correct conclusion?
Degrees of freedom (DOF)
Hard
A.Two joints are sufficient because the task is planar
B.Four independent DOF are required for every planar task
C.Three independent DOF are required for the stated task
D.Two joints are sufficient only at singular configurations
Correct Answer: Three independent DOF are required for the stated task
Explanation:
The task specifies two positional variables and one orientation variable, giving a three-dimensional task space even though motion is planar.
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49A robot has seven independently actuated joints but performs a task whose end-effector pose requires six coordinates. What property does the extra joint provide when the Jacobian has full row rank?
Degrees of freedom (DOF)
Hard
A.Underactuation of the end-effector pose
B.A reduction in the dimensionality of joint space
C.Guaranteed elimination of all singularities
D.Kinematic redundancy for obstacle avoidance or optimization
Correct Answer: Kinematic redundancy for obstacle avoidance or optimization
Explanation:
Seven joints controlling a six-dimensional pose provide one redundant DOF that can be used for secondary objectives such as avoiding obstacles.
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50A camera detects an object at coordinates . The camera is mounted on the robot wrist, and the wrist pose relative to the robot base is . Which expression gives the object position in the base frame using homogeneous coordinates?
Robot coordinate systems
Hard
A.
B.
C.
D.
Correct Answer:
Explanation:
A homogeneous transform maps a point from the camera frame into the base frame by left-multiplication: .
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51A tool must maintain a fixed orientation relative to the workpiece while the robot base rotates about a vertical axis. Which coordinate frame is most appropriate for defining the tool path?
Robot coordinate systems
Hard
A.The joint encoder frame
B.The motor commutation frame
C.The workpiece or task frame
D.The robot base frame
Correct Answer: The workpiece or task frame
Explanation:
Defining the path in the workpiece frame preserves the intended geometric relationship even when the robot base or mounting orientation changes.
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52A spherical-wrist manipulator has a nominal reach envelope that includes a target point, but the required tool orientation cannot be achieved there. What distinction explains this result?
Robot workspace
Hard
A.The point is inside the singular workspace by definition
B.The point is outside both workspaces because orientation is irrelevant
C.The point is in the dexterous workspace but outside the reachable workspace
D.The point is in the reachable workspace but outside the dexterous workspace
Correct Answer: The point is in the reachable workspace but outside the dexterous workspace
Explanation:
Reachable workspace concerns position alone, whereas dexterous workspace requires the desired orientations to be attainable at that position.
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53Two consecutive links of a planar two-revolute-joint robot have lengths and . Ignoring joint limits and link thickness, which radial distances can its end effector reach?
Robot workspace
Hard
A.
B. regardless of link ordering
C. for all positive link lengths
D.
Correct Answer:
Explanation:
The maximum radius occurs when links align, and the minimum occurs when they oppose each other, giving the annular range to .
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54In a serial articulated robot, the shoulder and elbow joints determine the wrist-center position, while three intersecting wrist axes determine tool orientation. Which structural feature is being described?
Robot anatomy
Hard
A.A differential-drive platform with a steering wrist
B.A cylindrical robot with a telescoping wrist
C.A six-axis robot with a spherical wrist
D.A parallel mechanism with passive joints
Correct Answer: A six-axis robot with a spherical wrist
Explanation:
The separation of positioning joints from three intersecting orientation joints is the defining anatomy of a six-axis articulated robot with a spherical wrist.
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55A robot's final link bends under payload, causing the gripper orientation to deviate even though joint angles are accurately measured. Which anatomical element is directly associated with the affected pose?
Robot anatomy
Hard
A.The fixed base and mounting plate
B.The end effector and wrist assembly
C.The power supply and safety relay
D.The controller enclosure and teach pendant
Correct Answer: The end effector and wrist assembly
Explanation:
The wrist and end effector form the terminal portion of the kinematic chain, so deformation there directly changes tool pose.
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56A manipulator uses three mutually orthogonal prismatic joints. Its motion envelope is a rectangular box, and its orientation remains fixed unless an external tool mechanism is added. Which manipulator type is it?
Types of robotic manipulators
Hard
A.Cartesian manipulator
B.Cylindrical manipulator
C.Polar manipulator
D.Articulated manipulator
Correct Answer: Cartesian manipulator
Explanation:
Three orthogonal linear axes produce Cartesian motion and a box-shaped workspace, characteristic of a Cartesian or gantry manipulator.
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57A robot requires a large vertical stroke, rotation around a central column, and radial extension. Which manipulator architecture best matches these requirements?
Types of robotic manipulators
Hard
A.Cylindrical manipulator
B.SCARA manipulator
C.Cartesian manipulator
D.Parallel delta manipulator
Correct Answer: Cylindrical manipulator
Explanation:
A cylindrical manipulator combines rotary motion about a vertical axis with radial and vertical linear motions.
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58A differential-drive robot must move sideways without changing its heading. Under ideal nonholonomic wheel constraints, what is the correct conclusion?
Mobile robots
Hard
A.It cannot instantaneously move sideways without reorienting
B.It can translate sideways through equal wheel speeds
C.It can translate sideways only while reversing
D.It can move sideways whenever both wheels are locked
Correct Answer: It cannot instantaneously move sideways without reorienting
Explanation:
Differential drive directly controls forward velocity and yaw rate, but lateral velocity is constrained to zero at the wheel contact model.
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59A four-wheel omnidirectional mobile robot uses independently driven Swedish wheels. Compared with a conventional differential-drive robot, what capability is added?
Mobile robots
Hard
A.Unlimited traction on every surface
B.Passive suspension without any additional hardware
C.Direct lateral motion without rotating the chassis
D.Perfect localization without external sensing
Correct Answer: Direct lateral motion without rotating the chassis
Explanation:
Swedish or mecanum wheels generate controllable velocity components in multiple directions, enabling lateral translation while maintaining heading.
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60An industrial robot repeats a high-speed welding path inside a guarded cell, while a hospital robot transports supplies among people and must react to changing routes. Which design priority differs most between the two systems?
Industrial and service robots
Hard
A.Manual teaching for the industrial robot and no sensing for the service robot
B.Human interaction for the industrial robot and fixed sequencing for the service robot
C.Low precision for the industrial robot and maximum payload for the service robot
D.Repeatability for the industrial robot and safe interaction for the service robot
Correct Answer: Repeatability for the industrial robot and safe interaction for the service robot
Explanation:
Industrial robots commonly prioritize speed and repeatability in structured cells, whereas service robots require perception, navigation, and safety around people.
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