Quiz sheet for EMF souces

The more practical unit of electrical energy is the:

A) kilojoule second

B) kilowatt second

C) kilowatt hour

D) kilojoule hour

ANSWER: C

The power losses in a system may be determined from the relationship, losses equal

A) output divided by input

B) input divided by output

C) input minus output

D) output minus input 

ANSWER: C

To increase the efficiency of any system the item that must be reduced is the:

A) time the system operates

B) output

C) input

D) losses

ANSWER: D

A generator produces electricity due to relative motion between a conductor and

A) an insulator

B) a capacitor

C) a resistor

D) a magnetic field

ANSWER: D

A photovoltaic cell converts

A) radiant energy to electrical energy

B) chemical energy to electrical energy

C) mechanical energy to electrical energy

D) kinetic energy to electrical energy

ANSWER: A

An electric motor operates due to

A) the heating effect of current

B) a chemical effect of current

C) the physiological effect of current

D) the magnetic effect of current

ANSWER: D

When two dissimilar metals are in contact and moisture is present, galvanic action occurs which causes

A) heat

B) light

C) resistance 

D) corrosion

ANSWER: D

The effects of current which are always present when an electric current flows, are the magnetic effect and the

A) physiological effect

B) heating effect

C) chemical effect

D) electrolytic effect

ANSWER: B

A positive ion is an atom that has.

A) been rendered electrically neutral 

B) gained an electrical charge

C) lost an electron

D) gained an electron

ANSWER: C

A positive ion is an atom that has.

A) been rendered electrically neutral 

B) gained an electrical charge

C) lost an electron

D) gained an electron

ANSWER: C

In the atomic structure of an element, a positive charge is exhibited by the:

A) Proton

B) Atom

C) Neutron

D) Electrons

ANSWER: A

The S.I. unit of electric charge is the 

A) Coulomb

B) capacitor 

C) ampere

D) volt

ANSWER: A

A solution capable of conducting an electrical current is called:

A) an electrolysis 

B) a dielectric solution

C) an electrolyte

D) a hydroelectric solution

ANSWER: C

The S.I. unit of force is the 

A) Newton

B) Newton metre 

C) Newton metre per second

D) Newton per watt

ANSWER: A

The rate of change in speed of a body is called 

A) Acceleration

B) Force

C) Pressure

D) velocity 

ANSWER: A

When any two quantities are related by graph, the one which is changed by the experimenter is called the

A) Independent variable

B) dependent variable 

C) independent constant 

D) dependent constant 

ANSWER: A

Which of the following is expressed in engineering notation? 

A) 5.34 x 101

B) 5.34 x 102

C) 5.34 x 106

D) 5.34 x 105

ANSWER: C

Opposition to electric current flow is termed 

A) resistance

B) reluctance

C) inductance

D) capacitance 

ANSWER: A

Opposition to electric current flow is termed 

A) resistance

B) reluctance

C) inductance

D) capacitance 

ANSWER: A

Opening the main switch in a circuit will 

A) reduce the supply voltage

B) reduce the circuit resistance

C) increase power flow

D) stop circuit current flow

ANSWER: D

Electrical pressure is measured by a 

A) Voltmeter

B) Ammeter

C) Ohmmeter 

D) manometer 

E) A manometer uses a water column to measure pressure 

ANSWER: B

A low circuit resistance causes 

A) the current o flow slowly 

B) high current

C) low current

D) no current

ANSWER: B

To measure d.c. current with an ammeter the meter must be connected in 

A) series 

B) parallel 

C) across the resistor

D) across the supply 

ANSWER: A

Doubling the voltage applied to a circuit will cause the 

A) resistance to double

B) resistance to halve

C) current to double 

D) current to halve

ANSWER: C

The capacity or ability to do work it called 

A) Power

B) Energy 

C) Force 

D) Torque

ANSWER: A

Electrical equipment is rated in terms of 

A) Power and Voltage

B) Power and energy

C) Current and voltage

D) Voltage and energy

ANSWER: A

The apparent change in position of the pointer of an analog meter is defined as 

A) Parallel error

B) Parallax error

C) Analogue error

D) Display error

ANSWER: B

The effect of current used in the operation of most electrical machines is the 

A) heating effect

B) chemical effect

C) magnetic effect

D) bruce effect

ANSWER: C

A copper conductor has a resistance of 2 ohms. Another copper conductor with the same length but half the cross sectional area will have a resistance of

A) 1 ohm

B) 2 ohms

C) 4 ohms

D) 8 ohms

ANSWER: C

To ensure an accurate reading when using an ohm-meter it is important to:

A) select the highest range.

B) select the lowest range.

C) check the zero reading.

D) estimate the value being measured.

ANSWER: C

Last modified: Tuesday, 1 June 2021, 10:47 AM