Free Printable Unit 103: Electrical scientific principles and technologies

1.

What is $\frac{3}{8}$ converted to a decimal?

a)

0.375

b)

2.67

c)

0.725

d)

0.4

2.

13m of a 50m drum of cable is used. What is the percentage left on the drum?

a)

26%

b)

50%

c)

74%

d)

13%

3.

Make resistivity the subject of the formula, R = $\frac{\rho L}{A}$ .

a)

$\rho = \frac{RA}{L}$

b)

$\frac{AL}{\rho}$

c)

$\frac{\rho L}{A}$

d)

$\frac{L}{RA}$

4.

Rearrange the following formula to make 'c' the subject: $a^2 = b^2 + c^2$

a)

$c = \sqrt{a^2 - b^2}$

b)

$c = \sqrt{b^2 - a^2}$

c)

$c = \sqrt{a^2 + b^2}$

d)

$c = \sqrt{b^2 + a^2}$

5.

How can 25kV be expressed in a different way?

a)

$25 \times 10^6V$

b)

$25 \times 10^3V$

c)

$25 \times 10^{-3}V$

d)

$25 \times 10^{-6}V$

6.

23mA can also be shown as how?

a)

23 ×10^3A

b)

23 ×10^6A

c)

$23 \times 10^{-3}A$

d)

23 × $10^{-6}A$

7.

What is the missing side of the triangle shown below?

a)

7.5

b)

9.3

c)

6.9

d)

9.5

8.

What formula will give the value of the hypotenuse of the triangle below?

a)

$\frac{5.2}{\cos 36}$

b)

h = $5.2 \times \cos 36$

c)

$\frac{5.2}{\sin 36}$

d)

h = 5.2 \times \sin 36

9.

What formula will give the angle indicated, θ, in the triangle shown?

a)

θ = $\cos^{-1}\left(\frac{6.6}{7}\right)$

b)

θ = $\sin^{-1}\left(\frac{6.6}{7}\right)$

c)

θ = $\cos\left(\frac{6.6}{7}\right)$

d)

θ = $\sin\left(\frac{6.6}{7}\right)$

10.

What is the value of the resistance, R, in the triangle below?

a)

7Ω

b)

5.3Ω

c)

3.8Ω

d)

6Ω

11.

What is the angle, θ, in the triangle shown below?

a)

27.28°

b)

8.91°

c)

58.96°

d)

62.71°

12.

Four different meters are used to measure the resistance of a CPC. What is the average reading if, individually they were: 1.3Ω, 1.05Ω, 1.24Ω, 1.12Ω

a)

1.18Ω

b)

1.2Ω

c)

4.71Ω

d)

1.51Ω

13.

An ohmmeter takes five readings on a circuit: 0.24Ω, 0.79Ω, 0.26Ω, 0.35Ω, 0.56Ω. What is the ‘range’ of the readings?

a)

0.55Ω

b)

0.79Ω

c)

0.24Ω

d)

2.16Ω

14.

The SI unit m² is used for what measurement?

a)

Volume

b)

Mean area

c)

Area

d)

Mass

15.

What are the SI base units for volume and temperature?

a)

m³, °C

b)

m³, °K

c)

m², °C

d)

m², °K

16.

What is the volume of a room that measures, 6m long by 3.9m wide and is 250cm high?

a)

12.4m³

b)

23.4m²

c)

23.4m³

d)

58.5m³

17.

An industrial motor has a mass of 500kg at sea level. What is the mass of the motor when it is taken 1000m above sea level?

a)

5000kg

b)

4.9kN

c)

5000N

d)

500kg

18.

What is the correct formula to determine mass?

a)

force x distance

b)

force x gravity

c)

density x volume

d)

density/volume

19.

Convert 2 1/2 minutes into the correct base unit.

a)

2 minutes, 30 seconds

b)

1/24th of an hour

c)

150s

d)

170s

20.

What is 0°K approximately in centigrade?

a)

-273°C

b)

273°C

c)

-459°C

d)

0°C

21.

What is the SI unit for frequency?

a)

Hz

b)

S

c)

mS

d)

J

22.

What is the SI unit for power?

a)

MW

b)

mW

c)

W

d)

kW

23.

What is inductive reactance measured in?

a)

Henrys

b)

Farads

c)

Ohms

d)

Watts

24.

What is the symbol for current?

a)

I

b)

A

c)

mA

d)

Ω

25.

What does EMF stand for?

a)

Electro-magneto force

b)

Electro-motive force

c)

Electron motive force

d)

Electron magneto force

26.

What does the sub-multiple, ‘PICO’ mean?

a)

×10⁻⁶

b)

×10⁻¹²

c)

×10⁻⁹

d)

×10⁻¹⁵

27.

What is reactive power also known by?

a)

KVAR

b)

W

c)

KVA

d)

kW

28.

What is the correct formula for resistance?

a)

$\frac{P}{I^2}$

b)

R = VI

c)

$\frac{I}{V}$

d)

$\frac{P}{I}$

29.

What are the correct units for capacitance and inductance?

a)

Farad and ohms

b)

Farad and henry

c)

Reactance and ohms

d)

Reactance and resistance

30.

What is true power?

a)

kVA

b)

VA

c)

kW

d)

kVAr

31.

What range would an ohmmeter be set to for the most accurate reading of a 1.99Ω cable?

a)

0–100Ω

b)

0–1kΩ

c)

0–10kΩ

d)

0–100kΩ

32.

If 400V supplied to a circuit that draws 14A, what is the power being consumed by the circuit?

a)

5.6kW

b)

28.57W

c)

0.035W

d)

56kW

33.

What is the best instrument to measure frequency?

a)

Low reading ohmmeter

b)

High reading ohmmeter

c)

Voltmeter

d)

Oscilloscope

34.

What is the meter in the diagram measuring?

a)

Current

b)

Power

c)

Energy

d)

Voltage

35.

What is the meter in the diagram measuring?

a)

Current

b)

Voltage

c)

Power

d)

Energy

36.

What is impedance measured in?

a)

Ohms

b)

Volts

c)

Amperes

d)

Watts

37.

A rocket has a mass of 1000 metric tons on earth. What is the rockets’ mass once it reaches Mars? (Ignore the fuel.)

a)

100 metric ton

b)

1981 metric tons

c)

100 metric tons

d)

1000 metric tons

38.

Impedance is made up of what components?

a)

Resistance and power

b)

Resistance and reactance

c)

Reactance and reluctance

d)

Current and resistance

39.

How much does a 5kg cable drum weigh?

a)

5kg

b)

5N

c)

49.05N

d)

10N

40.

What is the distance between the fulcrum and load ‘B’ if the lever is in equilibrium in the diagram below?

a)

0.5m

b)

2m

c)

8m

d)

1m

41.

What is the load being lifted in the diagram below?

a)

36N

b)

1440N

c)

360N

d)

3531kg

42.

Pincers pulling out a nail can be described as what?

a)

A pulley

b)

A cantilever

c)

A lever

d)

A lintel

43.

What is the value of gravity at sea level?

a)

9.81mS⁻²

b)

90.8mS⁻²

c)

10mS⁻¹

d)

9.81mS²

44.

A 1000kg transformer exerts a force of what on the ground?

a)

9.81kN

b)

100N

c)

981N

d)

98kN

45.

Joules and watts are measurements of what?

a)

Energy and voltage

b)

Energy and current

c)

Power and inductance

d)

Energy and power

46.

A cable drum has a mass of 10kg and is lifted 2.5m to a shelf. How much energy is used?

a)

25J

b)

25N

c)

245.25W

d)

245.25J

47.

What is the energy stored in a drill called when it is sitting on the floor?

a)

Kinetic

b)

Potential

c)

Centripetal

d)

Centrifugal

48.

A drill falling off a ladder has what type of energy?

a)

Centripetal

b)

Centrifugal

c)

Kinetic

d)

Potential

49.

How much power is used when 200J of energy is expended in moving a load in 3.4 seconds?

a)

58.82W

b)

680W

c)

577W

d)

200W

50.

A 45kg motor is lifted 3m in to a shelf in 5 seconds. How much power is used?

a)

675W

b)

264.87W

c)

6.62kW

d)

660W

51.

A crane uses 3.4kW of power to lift a 200kg mass in 6.7s. How far did the load move?

a)

111.7m

b)

1117.36m

c)

11.61m

d)

4.556km

52.

A 109kg mass is moved to a height of 10m in 16s. What power is used?

a)

668.3W

b)

10.69kW

c)

17.44kW

d)

290W

53.

How long does it take to move a load if 1000W of power is used and 2000J of energy is expended?

a)

0.5s

b)

55 hours

c)

25

d)

5.5 hours

54.

Current is the flow of what?

a)

Electrons

b)

Protons

c)

Neutrons

d)

Atoms

55.

What atoms are least densely packed?

a)

Water at –273°C

b)

Steam

c)

Water

d)

Ice

56.

What is an insulator?

a)

A material with lots of electrons in the outer shell

b)

A material with freely moving electrons

c)

A material with few electrons in the outer shell

d)

A material with freely moving protons

57.

What is a conductor?

a)

A material with freely moving electrons

b)

A material with lots of electrons in the outer shell

c)

A material with tightly bound electrons in the outer shell

d)

A material with freely moving protons

58.

What happens if you heat an aluminium conductor?

a)

The resistance increases

b)

The resistance decreases

c)

The impedance decreases

d)

The reactance improves

59.

What application is mineral insulated cable particularly suitable for?

a)

Fire alarm cable

b)

Connections to motors

c)

Domestic sockets

d)

Domestic lighting

60.

What application is thermosetting steel wire armored cable particularly suited to?

a)

Domestic lighting

b)

Boiler connection

c)

Domestic sockets

d)

Feeding an outbuilding

61.

What is the resistance of 120m of copper 4mm² cable if it has a resistivity of 0.0178μΩ/m?

a)

1.5Ω

b)

6.8Ω

c)

0.534Ω

d)

8.54Ω

62.

Steel conduit with a resistivity of 0.12μΩ/m and an overall CSA of 34mm² is to be used as a circuit CPC. What is the resistance if the conduit run is 20m?

a)

0.071Ω

b)

7Ω

c)

0.5Ω

d)

1Ω

63.

If resistors are added up to find the total circuit resistance, what type of circuit is it?

a)

Combined series and parallel

b)

Shunt

c)

Series

d)

Parallel

64.

If resistors are added up using reciprocals to find the total circuit resistance, what type of circuit is it?

a)

Parallel

b)

Series

c)

Combined series and parallel

d)

Reactive

65.

What is the resistance of a circuit if the current drawn from a 400V supply is 17.3A?

a)

23.12Ω

b)

0.043Ω

c)

2.3Ω

d)

4.3Ω

66.

What current is drawn from a 200V supply if a 4Ω load is connected?

a)

0.02A

b)

20A

c)

5A

d)

50A

67.

Which of the following is not an ohms law equation?

a)

V = RI

b)

V = IR

c)

I = V/R

d)

R = VI

68.

If four equal resistors are connected in series and then across a 230V supply what will be the voltage across a single resistor?

a)

920V

b)

9.2V

c)

57.5V

d)

230V

69.

If 5 × 2Ω resistors are connected in series and then to a 115V supply, what will be the current drawn by the circuit?

a)

57.5A

b)

230A

c)

2.3A

d)

11.5A

70.

If six resistors are connected in parallel and they are all 12Ω, what is the total circuit resistance?

a)

24Ω

b)

6Ω

c)

2Ω

d)

12Ω

71.

If a 6Ω resistor is connected in series with a 13Ω resistor and then connected across a 220V supply, what is the total circuit power consumption?

a)

2.86 kW

b)

2.55kW

c)

4.18kW

d)

15kW

72.

4 × 5Ω resistors are connected in series. What is the voltage drop across the first resistor if the supply is 115V?

a)

28.75V

b)

23V

c)

0V

d)

115V

73.

If four resistors of 29Ω each are connected in parallel, what is the total power of the circuit if the supply is 200V?

a)

6.9W

b)

23.2kW

c)

200W

d)

5.52kW

74.

A line conductor measures 0.66Ω and the neutral measures 0.67Ω. What is the voltage drop of the circuit if connected to a domestic supply with a design current of 5A?

a)

3.96A

b)

4.02V

c)

6.65A

d)

6.65V

75.

The line and neutral conductors measure 0.44Ω each and the CPC measures 0.56Ω. If they are connected to a load that is designed to take 10A, what is the volt drop on the circuit?

a)

8.8V

b)

12V

c)

10V

d)

5.6V

76.

If two dissimilar metals are connected by a cell at one end, and the other ends placed in a conductive solution, what will happen?

a)

Condensation

b)

Electrolysis

c)

Osmosis

d)

Insulation

77.

From the diagram below, what voltage will be dropped across the load?

a)

76.67V

b)

228.11V

c)

3.29V

d)

1.89V

78.

What is the current flowing through the 6Ω resistor?

a)

0.24A

b)

3A

c)

4A

d)

144A

79.

From the diagram below, what voltage will be dropped across the 50Ω load?

a)

4.6V

b)

228.17V

c)

227.32V

d)

226.42V

80.

What is the total resistance of the circuit shown below?

a)

10Ω

b)

13Ω

c)

0.361Ω

d)

1Ω

Unit 103: Electrical scientific principles and technologies

Total questions: 80

Worksheet time: 40mins

Similar Resources on Wayground