Q21. What is the SI unit of stress?
Correct: Pascal
Stress is measured in Pascal.
Q22. Which instrument measures electric current?
Correct: Ammeter
Ammeter measures current.
Q23. What is the unit of power?
Correct: Watt
Power is measured in Watt.
Q24. Which metal is used in electrical wiring?
Correct: Copper
Copper has high conductivity.
Q25. What is the unit of frequency?
Correct: Hertz
Frequency is measured in Hertz.
Q26. Which law relates voltage, current and resistance?
Correct: Ohm's law
Ohm's law relates V, I and R.
Q27. What is the unit of torque?
Correct: Nm
Torque is measured in Newton-meter.
Q28. Which device converts AC to DC?
Correct: Rectifier
Rectifier converts AC to DC.
Q29. Which material is used as an insulator?
Correct: Rubber
Rubber is an insulator.
Q30. What is the unit of energy?
Correct: Joule
Energy is measured in Joule.
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