Electrical Pre-engineering Certification Prep RECF

A motor on a train converts 160,000 J of electrical energy into 80,000 J of kinetic energy. How efficient is the motor?

• 80%

• 75%

• 200%

• 50%

Which of the following is not measured by frequency?

• Light

• Heat

• Line Current

• Sound

What is the unit of frequency?

• Newton

• Hertz

• Joule

• Watt

If a light bulb converts 100 J of electrical energy into 20 J of light energy, what is its efficiency?

• 20%

• 50%

• 80%

• 100%

Which of the following is a form of energy that can be measured in joules?

• Temperature

• Pressure

• Sound

• Force

A motor on a train converts 60000 J of electric into 45000 J.

• 15kJ

• 20kJ

• 10kJ

• 25kJ

Calculate the potential energy of an object with a mass of 10 kg raised to a height of 5 m. (Use g = 9.81 m/s²)

• 49.05 J

• 98.1 J

• 490.5 J

• 981 J

Answer explanation

Potential Energy = mass × height × g

If a device uses 1.5 kW for 4 hours, how many kilowatt-hours (kWh) of energy does it consume?

• 1.5 kWh

• 4 kWh

• 6 kWh

• 12 kWh

Answer explanation

Energy = Power × Time)

What type of sensor would you use to measure distance with ultrasonic waves?

• • Optical Shaft Encoder

• Ultrasonic Sensor

• Gyroscopic Sensor

• Accelerometer

Which sensor is commonly used for measuring angular position?

• • A) Potentiometer

• B) Ultrasonic

• C) Light sensor

• D) Limit switch