Robotics Worksheet: DC and Servo Motors
Robot tip (Spin or point): DC motor: spins continuously; swap its wires to reverse it. Servo: goes to a set angle between 0° and 180°. Servo turn = bigger angle − smaller angle (30° to 120° = 90°). A program like angle = 90, angle = angle + 30 adds and takes away degrees in order.
NameDateTime takenScore ___ / 40
- 1.⚙️ A motor changes electrical energy into … (a) sound only (b) water (c) light (d) movement
- 2.True or false: “usually turns 0° to 180°” is true of a DC motor. (a) True (b) False
- 3.🦾 A servo arm points right at 0°, straight up at 90° and left at 180°. It is set to 135°. Where does the arm point? (a) points up and right (b) points up and left (c) points left (d) points straight up
- 4.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 180°?
- 5.⚙️ Which motor is best for spinning a robot’s wheels round and round? (a) a light sensor (b) a servo motor (c) a DC motor (d) a buzzer
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6.🦾 A servo program runs:
angle = 0
angle = angle + 10
angle = angle + 20
angle = angle − 20
To what angle (in degrees) does the servo turn in the end? -
7.🦾 A servo program runs:
angle = 120
angle = angle − 60
angle = angle − 30
To what angle (in degrees) does the servo turn in the end? - 8.True or false: “turns to an exact angle” is true of a servo motor. (a) False (b) True
- 9.⚙️ DC motor or servo motor: which one moves an arm joint? (a) a DC motor (b) a servo motor
- 10.⚙️ Which motor is best for turning a robot arm to exactly 45°? (a) a fan (b) a buzzer (c) a DC motor (d) a servo motor
- 11.🦾 A servo arm points right at 0°, straight up at 90° and left at 180°. It is set to 0°. Where does the arm point? (a) points straight up (b) points left (c) points right (d) points up and right
- 12.⚙️ DC motor or servo motor: which one spins faster with more V? (a) a servo motor (b) a DC motor
- 13.🦾 A servo moves from 40° to 70°. How many degrees does it turn?
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14.🦾 A servo program runs:
angle = 90
angle = angle − 10
angle = angle − 40
angle = angle + 60
angle = angle − 50
To what angle (in degrees) does the servo turn in the end? - 15.⚙️ How do you make a DC motor spin the other way? (a) shake it (b) paint it red (c) swap its two wires (d) add more wheels
- 16.🦾 A servo arm points right at 0°, straight up at 90° and left at 180°. It is set to 90°. Where does the arm point? (a) points up and right (b) points straight up (c) points up and left (d) points left
- 17.⚙️ DC motor or servo motor: which one spins round and round? (a) a DC motor (b) a servo motor
- 18.🦾 A servo moves from 170° to 160°. How many degrees does it turn?
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19.🦾 A servo program runs:
angle = 20
angle = angle + 10
angle = angle + 60
angle = angle − 30
angle = angle + 10
To what angle (in degrees) does the servo turn in the end? - 20.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 30°?
- 21.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 90°?
- 22.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 120°?
- 23.⚙️ DC motor or servo motor: which one holds a set angle? (a) a DC motor (b) a servo motor
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24.🦾 A servo program runs:
angle = 20
angle = angle + 40
angle = angle − 40
To what angle (in degrees) does the servo turn in the end? - 25.True or false: “moves an arm joint” is true of a servo motor. (a) False (b) True
- 26.True or false: “holds a set angle” is true of a servo motor. (a) True (b) False
- 27.True or false: “has a signal wire” is true of a DC motor. (a) True (b) False
- 28.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 60°?
- 29.⚙️ DC motor or servo motor: which one reverses if wires swap? (a) a DC motor (b) a servo motor
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30.🦾 A servo program runs:
angle = 90
angle = angle − 60
angle = angle + 20
To what angle (in degrees) does the servo turn in the end? - 31.⚙️ DC motor or servo motor: which one drives the wheels? (a) a servo motor (b) a DC motor
- 32.⚙️ DC motor or servo motor: which one has just two wires? (a) a DC motor (b) a servo motor
- 33.True or false: “reverses if wires swap” is true of a servo motor. (a) False (b) True
- 34.⚙️ DC motor or servo motor: which one usually turns 0° to 180°? (a) a DC motor (b) a servo motor
- 35.⚙️ A common servo can turn from 0° up to about … (a) 180° (b) 18° (c) 10° (d) 1800°
- 36.🦾 A servo arm points right at 0°, straight up at 90° and left at 180°. It is set to 45°. Where does the arm point? (a) points up and left (b) points straight up (c) points up and right (d) points right
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37.🦾 A servo program runs:
angle = 130
angle = angle + 50
angle = angle − 10
To what angle (in degrees) does the servo turn in the end? - 38.True or false: “spins round and round” is true of a DC motor. (a) True (b) False
- 39.True or false: “moves an arm joint” is true of a DC motor. (a) True (b) False
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40.🦾 A servo program runs:
angle = 30
angle = angle − 10
angle = angle + 30
angle = angle + 60
angle = angle − 10
To what angle (in degrees) does the servo turn in the end?
Answer key
- movement
- False
- points up and left
- 300
- a DC motor
- 10
- 30
- True
- a servo motor
- a servo motor
- points right
- a DC motor
- 30
- 50
- swap its two wires
- points straight up
- a DC motor
- 10
- 70
- 50
- 150
- 200
- a servo motor
- 20
- True
- True
- False
- 100
- a DC motor
- 50
- a DC motor
- a DC motor
- False
- a servo motor
- 180°
- points up and right
- 170
- True
- False
- 100
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