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 servo turns 60° every 100 ms. How many milliseconds does it take to turn 150°?
- 2.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 60°?
- 3.⚙️ A common servo can turn from 0° up to about … (a) 18° (b) 180° (c) 1800° (d) 10°
- 4.True or false: “turns to an exact angle” is true of a DC motor. (a) True (b) False
- 5.True or false: “usually turns 0° to 180°” is true of a DC motor. (a) False (b) True
- 6.True or false: “holds a set angle” is true of a servo motor. (a) False (b) True
- 7.⚙️ DC motor or servo motor: which one usually turns 0° to 180°? (a) a servo motor (b) a DC motor
- 8.⚙️ DC motor or servo motor: which one moves an arm joint? (a) a servo motor (b) a DC motor
- 9.True or false: “moves an arm joint” is true of a servo motor. (a) False (b) True
- 10.⚙️ A motor changes electrical energy into … (a) movement (b) water (c) sound only (d) light
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11.🦾 A servo program runs:
angle = 50
angle = angle + 20
angle = angle − 20
angle = angle + 10
angle = angle − 20
To what angle (in degrees) does the servo turn in the end? - 12.True or false: “spins faster with more V” is true of a DC motor. (a) True (b) False
- 13.⚙️ How do you make a DC motor spin the other way? (a) shake it (b) add more wheels (c) paint it red (d) swap its two wires
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14.🦾 A servo program runs:
angle = 60
angle = angle − 40
angle = angle − 20
angle = angle + 50
To what angle (in degrees) does the servo turn in the end? - 15.True or false: “drives the wheels” is true of a servo motor. (a) False (b) True
- 16.True or false: “spins round and round” is true of a DC motor. (a) True (b) False
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17.🦾 A servo program runs:
angle = 150
angle = angle − 60
angle = angle + 60
To what angle (in degrees) does the servo turn in the end? -
18.🦾 A servo program runs:
angle = 100
angle = angle + 60
angle = angle − 60
To what angle (in degrees) does the servo turn in the end? -
19.🦾 A servo program runs:
angle = 140
angle = angle + 10
angle = angle − 30
angle = angle − 10
To what angle (in degrees) does the servo turn in the end? - 20.🦾 A servo moves from 0° to 140°. How many degrees does it turn?
- 21.⚙️ Which motor is best for spinning a robot’s wheels round and round? (a) a buzzer (b) a DC motor (c) a light sensor (d) a servo motor
- 22.🦾 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 up and left (b) points left (c) points straight up (d) points right
- 23.⚙️ Which motor is best for turning a robot arm to exactly 45°? (a) a servo motor (b) a fan (c) a DC motor (d) a buzzer
- 24.True or false: “moves an arm joint” is true of a DC motor. (a) True (b) False
- 25.🦾 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 right (c) points left (d) points straight up
- 26.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 30°?
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27.🦾 A servo program runs:
angle = 10
angle = angle + 30
angle = angle + 30
angle = angle − 50
angle = angle + 30
To what angle (in degrees) does the servo turn in the end? - 28.True or false: “spins round and round” is true of a servo motor. (a) True (b) False
- 29.⚙️ DC motor or servo motor: which one turns to an exact angle? (a) a DC motor (b) a servo motor
- 30.⚙️ DC motor or servo motor: which one has a signal wire? (a) a DC motor (b) a servo motor
- 31.True or false: “turns to an exact angle” is true of a servo motor. (a) True (b) False
- 32.⚙️ DC motor or servo motor: which one has just two wires? (a) a servo motor (b) a DC motor
- 33.⚙️ DC motor or servo motor: which one drives the wheels? (a) a servo motor (b) a DC motor
- 34.🦾 A servo turns 60° every 100 ms. How many milliseconds does it take to turn 120°?
- 35.🦾 A servo moves from 60° to 170°. How many degrees does it turn?
- 36.🦾 A servo moves from 10° to 0°. How many degrees does it turn?
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37.🦾 A servo program runs:
angle = 40
angle = angle + 30
angle = angle − 20
angle = angle + 60
angle = angle + 60
To what angle (in degrees) does the servo turn in the end? - 38.True or false: “reverses if wires swap” is true of a DC motor. (a) False (b) True
- 39.True or false: “has just two wires” is true of a servo motor. (a) False (b) True
- 40.🦾 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 right (c) points up and left (d) points straight up
Answer key
- 250
- 100
- 180°
- False
- False
- True
- a servo motor
- a servo motor
- True
- movement
- 40
- True
- swap its two wires
- 50
- False
- True
- 150
- 100
- 110
- 140
- a DC motor
- points right
- a servo motor
- False
- points straight up
- 50
- 50
- False
- a servo motor
- a servo motor
- True
- a DC motor
- a DC motor
- 200
- 110
- 10
- 170
- True
- False
- points up and left
Free robotics lessons, practice and worksheets at talentjr.in/robotics-for-kids