Principles of electrical science C&G 1

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

Calculate the cosine of the following angle (a) in the figure below.

• 37.5

• 0.78

• 0.63

• 0.8

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

Calculate the effort required to lift a 10 Newton load with a crowbar in the figure below.

• 33 Newton’s

• 0.3 Newton’s

• 3.3 Newton’s

• 6 Newton’s