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Lower Saxony Vocational Gymnasium Mechatronics - independent engineering foundations study materials
Lower Saxony Vocational Gymnasium Mechatronics - independent engineering foundations study resources

Lower Saxony Vocational Gymnasium Mechatronics - independent engineering foundations practice questions

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Question 1Materials, testing and selection

Which value is normally used as the modulus of elasticity (Elastizitätsmodul) of structural steel S235 in engineering calculations?

  1. 70 000 N/mm²
  2. 210 000 N/mm² Correct answer.
  3. 21 000 N/mm²
  4. 2 100 N/mm²

Explanation

E ≈ 210 000 N/mm² (210 GPa) for all common structural steels. It links stress and strain in Hooke's law σ = E · ε and is essentially independent of the steel grade - S235 and S355 have the same stiffness but different yield strengths.

Question 2Materials, testing and selection

A round steel tie bar with a diameter of 20 mm carries an axial tensile force of 62.8 kN. What is the normal stress in the bar?

  1. ≈ 100 N/mm²
  2. ≈ 157 N/mm²
  3. ≈ 200 N/mm² Correct answer.
  4. ≈ 3 140 N/mm²

Explanation

S = π/4 · d² = π/4 · 20² = 314.2 mm². σ = F/S = 62 800 N / 314.2 mm² ≈ 200 N/mm². For S235 (Re = 235 N/mm²) this bar is already close to the yield point.

Question 3Materials, testing and selection

A steel rod of length 2 500 mm and cross-section 200 mm² is loaded with 42 kN. With E = 210 000 N/mm², how much does it elongate elastically?

  1. 2.5 mm Correct answer.
  2. 0.25 mm
  3. 25 mm
  4. 1.0 mm

Explanation

σ = F/S = 42 000/200 = 210 N/mm². ε = σ/E = 210/210 000 = 0.001. ΔL = ε · L = 0.001 · 2 500 mm = 2.5 mm. Equivalently ΔL = F·L/(E·S).

Question 4Materials, testing and selection

A cube of an unknown metal measuring 40 mm × 40 mm × 40 mm has a mass of 172.8 g. Which metal is it most likely to be?

  1. Aluminium (ρ ≈ 2.7 g/cm³) Correct answer.
  2. Steel (ρ ≈ 7.85 g/cm³)
  3. Copper (ρ ≈ 8.9 g/cm³)
  4. Magnesium (ρ ≈ 1.74 g/cm³)

Explanation

V = 4 cm × 4 cm × 4 cm = 64 cm³. ρ = m/V = 172.8 g / 64 cm³ = 2.70 g/cm³, which matches aluminium.

Question 5Materials, testing and selection

A galvanised (zinc-coated) steel sheet is scratched down to the bare steel. Why does the steel still not rust at the scratch?

  1. The zinc layer flows into the scratch and seals it mechanically
  2. Zinc is less noble than iron, so it becomes the anode and corrodes preferentially, protecting the steel cathodically Correct answer.
  3. Zinc is more noble than iron and therefore protects it as a cathode
  4. The zinc raises the carbon content of the steel locally, making it corrosion resistant

Explanation

In the electrochemical series zinc (≈ −0.76 V) is less noble than iron (≈ −0.44 V). In the presence of an electrolyte the zinc dissolves as the sacrificial anode and the exposed steel becomes the cathode, where no metal dissolution occurs. This active (cathodic) protection is why galvanising still works at cut edges and scratches.

Question 6Materials, testing and selection

A square softwood post with a cross-section of 120 mm × 120 mm is loaded in compression parallel to the grain. If the permissible compressive stress is 8.5 N/mm², what is the maximum permissible axial load?

  1. ≈ 1.0 kN
  2. ≈ 61.2 kN
  3. ≈ 122.4 kN Correct answer.
  4. ≈ 1 224 kN

Explanation

A = 120 mm × 120 mm = 14 400 mm². F = σ · A = 8.5 N/mm² × 14 400 mm² = 122 400 N = 122.4 kN. (For a slender post a buckling check would also be required, which can reduce this value considerably.)

Question 7Materials, testing and selection

A tie rod of S235 steel (yield strength Re = 235 N/mm²) must carry a static tensile force of 90 kN with a safety factor of 1.5 against yielding. What is the minimum required cross-sectional area?

  1. ≈ 383 mm²
  2. ≈ 575 mm² Correct answer.
  3. ≈ 862 mm²
  4. ≈ 255 mm²

Explanation

σ_perm = Re / ν = 235 / 1.5 = 156.7 N/mm². A = F / σ_perm = 90 000 N / 156.7 N/mm² ≈ 574.5 mm². A round bar would need d = √(4A/π) ≈ 27.0 mm, so Ø28 mm would be selected.

Question 8Materials, testing and selection

A proportional tensile specimen has an original gauge length L0 = 100 mm and a diameter of 10 mm. After fracture the gauge length measures 117 mm, and the maximum force recorded during the test was 42.4 kN. What are the percentage elongation after fracture A and the tensile strength Rm?

  1. A = 17 %, Rm ≈ 540 N/mm² Correct answer.
  2. A = 17 %, Rm ≈ 424 N/mm²
  3. A = 117 %, Rm ≈ 540 N/mm²
  4. A = 14.5 %, Rm ≈ 540 N/mm²

Explanation

A = (Lu − L0)/L0 × 100 % = (117 − 100)/100 × 100 % = 17 %. S0 = π/4 · 10² = 78.54 mm², so Rm = 42 400 N / 78.54 mm² ≈ 540 N/mm². An elongation of 17 % indicates a ductile steel with substantial plastic reserve.

Question 9Statics, strength and mechanical transmission

A shaft of diameter d = 20 mm carries torque M = 40 N·m. Using the polar section modulus Wp = πd³/16, what is the approximate torsional shear stress τ = M/Wp?

  1. Approximately 25.5 N/mm² Correct answer.
  2. Approximately 2.5 N/mm²
  3. Approximately 255 N/mm²
  4. Approximately 0.25 N/mm²

Explanation

d = 20 mm → d³ = 8000 mm³; Wp = π·8000/16 ≈ 1570.8 mm³; τ = 40×10³ N·mm / 1570.8 mm³ ≈ 25.5 N/mm².

Question 10Statics, strength and mechanical transmission

A gear pair has driving gear z1 = 20 teeth and driven gear z2 = 60 teeth. Ideal speed ratio n2/n1 equals:

  1. 1/3 Correct answer.
  2. 3
  3. 1
  4. 80

Explanation

For external gears (ideal): n2/n1 = z1/z2 = 20/60 = 1/3 (speed reduces, torque increases).

Question 11Statics, strength and mechanical transmission

If a 3:1 speed-reducing gear stage is ideal and input torque is 4 N·m, output torque is approximately:

  1. 12 N·m Correct answer.
  2. 4/3 N·m
  3. 4 N·m
  4. 1 N·m

Explanation

Ideal power conservation: M·ω constant → torque scales with the inverse of speed → about 4 × 3 = 12 N·m (ignoring losses).

Question 12Statics, strength and mechanical transmission

A bolted joint must clamp with at least 2 kN. Using σ_allow = 100 N/mm² for the bolt tensile stress (simplified axial model), what minimum stress area is required?

  1. 20 mm² Correct answer.
  2. 2 mm²
  3. 200 mm²
  4. 0.5 mm²

Explanation

A = F/σ = 2000 N / 100 N/mm² = 20 mm² (simplified; real joints also consider preload, friction, and fatigue).

Question 13Statics, strength and mechanical transmission

A drive chain must deliver 2.0 kW at the load. Gearbox efficiency η = 0.90 and motor-inverter efficiency η_ei = 0.85 (both constant). Approximate electrical input power required is:

  1. About 2.61 kW Correct answer.
  2. About 2.00 kW (efficiencies can be ignored)
  3. About 1.53 kW
  4. About 0.20 kW

Explanation

P_in = P_out/(η·η_ei) = 2.0/(0.90·0.85) = 2.0/0.765 ≈ 2.61 kW. METRO 5 dimensioning must include real drive-chain losses.

Question 14Statics, strength and mechanical transmission

A load needs M = 6 N·m at n = 1000 min⁻¹. Using P = M·ω with ω = 2πn/60 ≈ 104.7 rad/s, required mechanical power is about:

  1. 628 W Correct answer.
  2. 6 W
  3. 1000 W
  4. 60 W

Explanation

P ≈ 6 · 104.7 ≈ 628 W. Select a motor/inverter chain with margin above this mechanical demand.

Question 15Statics, strength and mechanical transmission

A geared motor must provide 30 N·m at the output. The motor itself can supply 3 N·m. Ignoring losses, the required gear ratio (speed reduction) is about:

  1. 10:1 Correct answer.
  2. 1:10 (speed increase)
  3. 1:1
  4. 100:1

Explanation

Ideal torque multiplication equals speed reduction ratio: 30/3 = 10 → about 10:1 reduction (real designs add efficiency margin).

Question 16Electrical circuits, machines and digital logic

In a simple series circuit, a 12 V DC supply feeds two resistors R1 = 100 Ω and R2 = 200 Ω. What is the current through the circuit (Ohm's law, ideal sources)?

  1. 0.04 A Correct answer.
  2. 0.12 A
  3. 1.2 A
  4. 36 A

Explanation

Total resistance R = 100 + 200 = 300 Ω. I = U/R = 12/300 = 0.04 A (40 mA).

Question 17Electrical circuits, machines and digital logic

An LDR (light-dependent resistor) in a voltage divider is best categorized as:

  1. A sensor element whose resistance changes with illumination, enabling an electrical signal Correct answer.
  2. A mechanical gearbox
  3. A hydraulic pump
  4. A purely decorative LED with fixed resistance forever

Explanation

An LDR is a passive sensing element used to convert light information into an electrical quantity - relevant when analyzing sensor chains in mechatronic systems.

Question 18Electrical circuits, machines and digital logic

A counter increments on each rising edge of a parts sensor. Preset = 10, current = 9. One more valid rising edge yields:

  1. Current = 10 and typically a done/equals output becomes true Correct answer.
  2. Current = 0 automatically without reset logic
  3. Current = 90
  4. The PLC deletes the counter instruction permanently

Explanation

Zählfunktionen accumulate events until a preset; reaching preset asserts a done condition used in Ablaufsteuerungen.

Question 19Electrical circuits, machines and digital logic

An inverter (Wechselrichter) in a modern electric drive is primarily used to:

  1. Supply a motor with variable frequency/voltage to control speed/torque within the drive's rated limits Correct answer.
  2. Convert the motor into a hydraulic pump mechanically
  3. Replace all mechanical couplings with Bluetooth audio
  4. Measure only ambient light for an LDR

Explanation

METRO 5 includes Wechselrichter among electrical drive assemblies used when developing Antriebslösungen; VFDs control AC motor speed via variable frequency.

Question 20Measurement, feedback, PLC and automation

In a Blockschaltbild of a mechatronic system, arrows between blocks typically represent:

  1. Signals, energy, or material flows between functional units Correct answer.
  2. Only the birthdates of designers
  3. Only random decorative lines with no meaning
  4. Only legal contract clauses

Explanation

Block diagrams show functional units and the flows (signals/energy/material) linking them - a METRO 1 analysis tool.

Question 21Measurement, feedback, PLC and automation

A sensor outputs 0–10 V representing 0–100 °C linearly. What temperature corresponds to 4.0 V?

  1. 40 °C Correct answer.
  2. 4 °C
  3. 25 °C
  4. 100 °C

Explanation

Sensitivity = 10 V / 100 °C = 0.1 V/°C → T = 4.0 / 0.1 = 40 °C.

Question 22Measurement, feedback, PLC and automation

Why do METRO 1 learners relate electrical and mechanical quantities to each other?

  1. Mechatronic systems couple electrical and mechanical domains; quantities must be consistent across interfaces Correct answer.
  2. Because mechanical quantities never affect electrical design
  3. Because electrical power cannot convert to mechanical work in any machine
  4. Because the RRL forbids all calculations

Explanation

METRO 1 requires determining electrical and mechanical quantities and relating them - essential at electromechanical interfaces.

Question 23Measurement, feedback, PLC and automation

A DC motor draws 5 A at 24 V and delivers 100 W mechanical output. What is its efficiency η = P_out/P_in?

  1. Approximately 83% Correct answer.
  2. Approximately 20%
  3. Approximately 5%
  4. Approximately 100% with certainty and no losses

Explanation

P_in = 24·5 = 120 W; η = 100/120 ≈ 0.833 → ~83%. Real motors always have losses, so 100% is not assumed.

Question 24Measurement, feedback, PLC and automation

When extending a mechatronic system (METRO 1), selecting a component should primarily be based on:

  1. Functional requirements, interfaces, and dimensioning against operating quantities Correct answer.
  2. Only the packaging color of the component
  3. Only the alphabetical order of manufacturer names
  4. Only choosing the physically largest part available

Explanation

METRO 1 includes planning extensions, selecting parts, and dimensioning them to requirements - not cosmetic or arbitrary criteria.

Question 25Measurement, feedback, PLC and automation

A capacitive proximity sensor is generally better suited than an inductive sensor when the target material is:

  1. Non-metallic (e.g., plastic, glass, liquid level via dielectric change), within the sensor's design limits Correct answer.
  2. Only ferromagnetic steel at any distance unlimited
  3. Only glowing plasma in deep space
  4. Only superconducting magnets at absolute zero exclusively

Explanation

Capacitive sensors respond to dielectric/permittivity changes and can detect many non-metals; inductive sensors primarily detect metallic (especially ferrous) targets. Always stay within datasheet limits.

Question 26Measurement, feedback, PLC and automation

Which best describes a mechatronic system in METRO 1 analysis?

  1. An integrated system combining mechanics, electrics/electronics, and information processing Correct answer.
  2. A purely literary metaphor with no technical components
  3. A system that forbids all sensors and actuators
  4. A system made only of wood with no measurable quantities

Explanation

Mechatronics integrates mechanical structure, electrical actuation/sensing, and information processing - METRO 1 analyzes these coupled structures.

Question 27Measurement, feedback, PLC and automation

A strain-gauge bridge is used primarily to measure:

  1. Small mechanical deformations that can be related to force or stress Correct answer.
  2. Only radio station frequencies
  3. Only acoustic tempo of music
  4. Only the pH of acids without any mechanical link

Explanation

Strain gauges convert mechanical strain into resistance changes, commonly in force/torque sensing - relevant to relating mechanical and electrical quantities.

Question 28Measurement, feedback, PLC and automation

What distinguishes a Regelkreis from a Steuerkette?

  1. A Regelkreis feeds back the measured actual value and corrects toward the setpoint; a Steuerkette does not close that feedback loop Correct answer.
  2. A Regelkreis never uses sensors
  3. A Steuerkette always measures the output and compares to a setpoint
  4. They are identical terms with no technical difference

Explanation

Per classical control terminology (also reflected in METRO 2), Regelung uses feedback (Istwert vs Sollwert); Steuerung is open-loop influencing of outputs by inputs.

Question 29Measurement, feedback, PLC and automation

In a GRAFCET, a transition between steps becomes firable when:

  1. Its receptivity/condition is satisfied and the preceding step is active (per evolution rules) Correct answer.
  2. Any random amount of time has passed with no conditions
  3. The power supply is switched off
  4. The operator whispers the word 'skip'

Explanation

Transitions fire based on Boolean receptivities when upstream steps are active, evolving the chart according to GRAFCET rules.

Question 30Measurement, feedback, PLC and automation

A TON (on-delay) timer with preset 5 s starts timing when its input becomes true. The output becomes true:

  1. 5 s after the input becomes true (if input remains true) Correct answer.
  2. Instantly when the input becomes true, regardless of preset
  3. Only 5 s before the input becomes true
  4. Only when power is removed

Explanation

On-delay timing is a standard Zeitfunktion in control: output follows input after the delay while the condition persists (typical IEC timer behavior).

Question 31Measurement, feedback, PLC and automation

An inductive proximity switch detecting a steel target is typically classified as:

  1. A binary (switching) sensor providing on/off information Correct answer.
  2. A continuously variable 0–10 V torque calculator by itself with no electronics
  3. A hydraulic proportional valve
  4. A mechanical lead screw

Explanation

METRO 2/3 content distinguishes binary sensors (e.g., inductive) from continuous measurement chains; inductive prox switches are classic binary presence sensors.

Question 32Measurement, feedback, PLC and automation

Which device is an electrical actuator commonly used to switch higher-power loads under PLC/relay control?

  1. Contactor (Schütz) or relay Correct answer.
  2. Thermometer capillary only
  3. Spirit level
  4. Vernier caliper

Explanation

METRO 2 covers electrical actuators; relays/contactors are standard switching actuators. METRO 5 also lists Relais/Schütze among drive assemblies.

Question 33Measurement, feedback, PLC and automation

Why is a Systemtest / Inbetriebnahme step required after implementing a control solution?

  1. To verify safety, sequence correctness, and sensor/actuator wiring before productive use Correct answer.
  2. Because testing is forbidden by the RRL
  3. Only to erase all documentation
  4. Only to increase undocumented risks intentionally

Explanation

METRO 2 Inhalte include Systemtest und Inbetriebnahme; learners must reflect and document solutions including safety.

Question 34Measurement, feedback, PLC and automation

Which best describes an Ablaufsteuerung compared with a pure combinatorial Verknüpfungssteuerung?

  1. Ablaufsteuerung progresses through steps over time/events; combinatorial logic outputs depend only on the current input combination Correct answer.
  2. Ablaufsteuerung ignores all sensors
  3. Combinatorial logic always requires GRAFCET steps by definition
  4. They are indistinguishable in every textbook

Explanation

METRO 2 lists both Verknüpfungs- and Ablaufsteuerungen; sequential charts (e.g., GRAFCET) capture step history, unlike memoryless combinational logic.

Question 35Measurement, feedback, PLC and automation

An XOR of two bits is true when:

  1. Exactly one of the two bits is true Correct answer.
  2. Both bits are true
  3. Both bits are false
  4. The bits are equal

Explanation

XOR is true for unequal inputs - useful digital foundation for comparisons and some interlocks.

Question 36Measurement, feedback, PLC and automation

In a closed-loop speed control, the controlled variable (Regelgröße) is typically:

  1. Actual speed measured by a sensor (e.g., encoder/tachometer feedback) Correct answer.
  2. Only the operator's favorite color
  3. Only the unused spare PLC rack slot number
  4. Only the ambient humidity if speed is uncontrolled open-loop

Explanation

In a Regelkreis, the Regelgröße is the measured actual value compared with the Führungsgröße (setpoint).

Question 37Measurement, feedback, PLC and automation

Which disturbance (Störgröße) example fits a temperature Regelkreis for an oven?

  1. Opening the oven door / varying ambient losses that cool the chamber Correct answer.
  2. The temperature setpoint entered by the operator
  3. The heater power command issued by the controller as Stellgröße
  4. The temperature sensor reading used as Istwert

Explanation

Störgrößen affect the process independently of the intended setpoint; door openings are classic thermal disturbances.

Question 38Measurement, feedback, PLC and automation

A 4–20 mA transmitter represents 0–50 bar linearly. What pressure corresponds to 12 mA?

  1. 25 bar Correct answer.
  2. 12 bar
  3. 50 bar
  4. 0 bar

Explanation

Span = 16 mA for 50 bar → 8 mA above 4 mA is half span → 25 bar.

Question 39Measurement, feedback, PLC and automation

Why does METRO 3 emphasize datasheets and Kennlinien when selecting sensors?

  1. To match measuring range, accuracy, interface, and environmental limits to the process Correct answer.
  2. Because datasheets are purely decorative PDFs
  3. Because Kennlinien forbid calibration forever
  4. Because any sensor works for any quantity without limits

Explanation

METRO 3 requires choosing sensors using technologies, characteristic quantities, datasheets, and Kennlinien, then planning the sensor interface.

Question 40Measurement, feedback, PLC and automation

Sampling a 100 Hz sinusoidal signal requires a sampling frequency greater than:

  1. 200 Hz (Nyquist), preferably with margin Correct answer.
  2. 1 Hz
  3. 5 Hz
  4. 10 Hz

Explanation

Nyquist theorem: fs > 2·f_max. For 100 Hz content, fs must exceed 200 Hz; practical systems use higher rates and anti-alias filters.

Question 41Measurement, feedback, PLC and automation

Pick-and-place optimization that reduces cycle time while keeping quality typically evaluates:

  1. Path, grip strategy, parallelization, and reliable sensor confirmation of each step Correct answer.
  2. Only increasing speed with no interlocks or confirmation
  3. Only painting the robot faster
  4. Only removing all end-effectors

Explanation

METRO 4 Unterrichtshinweise cite economic, ergonomic, or technological optimization criteria for handling systems (robots, belts, pick-and-place).

Question 42Measurement, feedback, PLC and automation

E/A coupling vs fieldbus networking of plant sections mainly differs in that fieldbuses:

  1. Share a communication medium/protocol among many nodes instead of only hardwired point-to-point I/O copies Correct answer.
  2. Eliminate the need for any power supply
  3. Forbid all diagnostics
  4. Are identical to a single digital input wire always

Explanation

METRO 4 lists interfaces/networking examples such as E/A-Kopplung, Bussysteme, and OPC for connecting plant sections.

Question 43Measurement, feedback, PLC and automation

When synchronizing a conveyor and a robot pick station, the most critical interface issue is usually:

  1. Handshake signals/conditions that prevent picking when no part is present or the robot is not ready Correct answer.
  2. The color of the conveyor belt alone
  3. The brand of the cafeteria coffee machine
  4. Whether the robot's teaching pendant has a rubber cover

Explanation

Ablaufbeschreibungen and interface coupling in METRO 4 center on correct sequencing and interlocks between subsystems.

Question 44Measurement, feedback, PLC and automation

OPC (as cited among METRO 4 interface examples) is best understood as:

  1. A interoperability approach for exchanging process data between automation/software systems Correct answer.
  2. A type of pneumatic cylinder cushion
  3. A mechanical gear tooth profile standard only
  4. A culinary steaming method

Explanation

The RRL lists OPC alongside E/A-Kopplung and Bussysteme as examples of Vernetzung/Schnittstellen of plant sections.

Question 45Pneumatic and hydraulic model reasoning

A pneumatic cylinder has piston area A = 8 cm² and is pressurized at p = 5 bar (gauge). Ignoring friction and rod area, what force can it theoretically develop? (1 bar = 10 N/cm²)

  1. 400 N Correct answer.
  2. 40 N
  3. 13 N
  4. 4000 N

Explanation

F = p·A = 5 bar · 10 N/cm²/bar · 8 cm² = 400 N.

Question 46Pneumatic and hydraulic model reasoning

A linear actuator must provide at least 250 N. Available cylinders deliver 180 N, 220 N, and 300 N at the design pressure. Which selection is appropriate if only one cylinder may be used?

  1. 300 N cylinder Correct answer.
  2. 180 N cylinder
  3. 220 N cylinder
  4. Any cylinder because force rating is irrelevant

Explanation

Dimensioning requires meeting or exceeding the required force with margin for friction/dynamics as specified; only 300 N meets ≥250 N among the options.

Question 47Pneumatic and hydraulic model reasoning

A pneumatic 5/2 directional valve controlling a double-acting cylinder is best described as:

  1. A non-electrical (fluidic) actuator/control element directing compressed air to extend/retract the cylinder Correct answer.
  2. A device that stores PLC ladder logic
  3. A device that generates 230 V AC from air alone
  4. A binary light sensor

Explanation

METRO 2 includes electrical and non-electrical actuators; pneumatic valves are key non-electrical control elements in electropneumatic systems.

Question 48Pneumatic and hydraulic model reasoning

In electropneumatics, a typical signal chain for extending a cylinder is:

  1. Sensor/button → control logic (relay/PLC) → solenoid valve → cylinder motion Correct answer.
  2. Cylinder motion → creates the button press in the past
  3. Solenoid valve → directly computes GRAFCET without electricity
  4. Sensor → directly generates 10 bar air without a compressor or valve

Explanation

METRO 2 emphasizes selecting sensors/actuators and integrating them into Steuerungen - the classic input–logic–actuator chain.

Question 49Manufacturing, machining models and metrology

A gear drive has a driving pinion with 20 teeth running at 1 500 min⁻¹ and a driven gear with 75 teeth. What is the gear ratio i and the output speed?

  1. i = 3.75; n2 = 400 min⁻¹ Correct answer.
  2. i = 3.75; n2 = 5 625 min⁻¹
  3. i = 0.27; n2 = 5 625 min⁻¹
  4. i = 3.75; n2 = 1 500 min⁻¹

Explanation

i = z2/z1 = 75/20 = 3.75, and i = n1/n2, so n2 = n1/i = 1 500/3.75 = 400 min⁻¹. A ratio greater than 1 is a reduction: the output turns more slowly than the input, but with correspondingly higher torque.

Question 50Manufacturing, machining models and metrology

A motor delivers 4.0 kW at 1 500 min⁻¹. What torque does it produce?

  1. 2.67 Nm
  2. 25.5 Nm Correct answer.
  3. 160 Nm
  4. 255 Nm

Explanation

P = M · ω with ω = 2πn. Here ω = 2π × 1 500/60 = 157.1 rad/s, so M = P/ω = 4 000 W / 157.1 rad/s ≈ 25.5 Nm.