202: Principles of electrical science

Which is the correct formula to find I from the formula P = I²R?

• I = √(P/R)

• I = √(R/P)

• I² = P²/R²

• I² = R²/P²

The SI unit for Impedance is?

• Watts

• Henrys

• Hertz

• Ohm’s

The electrical quantities symbol for Inductive Reactance is?

• W

• X_L

• Y

• Z

Kelvin is the measurement of?

• Length

• Area

• Mass

• Temperature

Which instrument would be used to measure Power?

• Ohm meter

• Volt meter

• Watt meter

• Amp meter

The SI unit for Energy is the?

• Watts

• Joule

• Ohm

• Farad

A 25 kilogram bag of cement falls to the ground from a height of 5 meters. How much force will the bag hit the ground with?

• 245.25N

• 5J

• 125N

• 196.2J

A wheel barrow is an example of a:

• Class 1 lever

• Class 2 lever

• Class 3 lever

• Class 4 lever

One set of gears are connected together. The smaller cog has 12 teeth and the larger cog has 20 teeth. The smaller cog rotates 40 times per second. How many times per second will the larger cog rotate?

• 24 times per second

• 67 times per second

• 58 times per second

• 87 times per second

An electric motor has an input of 4kW and an output of 3.3KW. The efficiency of the motor is?

• 90%

• 100%

• 82.5%

• 121%