Answer ALL questions. Look for any feedback given if you get an answer incorrect. Keep choosing an answer until you get it correct. CORRECT or INCORRECT answers are indicated at the TOP of the page. A score is given at the TOP of the page when the exercise has been completed.
What type of components are shown here?
inductors
capacitors
resistors
thyristors
What type of components are shown here?
inductor, resistor, capacitor
capacitor, resistor, LED
resistor, inductor, transistor
thyristor, LED, inductor
Which one of the following does not affect the resistance of a conductor?
conductor material
CSA
temperature
conductor insulation
Which one of the following statements is true of a 'standard' conductor?
the resistance of a conductor is proportional to its length and proportional to its CSA
the resistance of a conductor is inversely proportional to its length and proportional to its CSA
the resistance of a conductor is proportional to its length and inversely proportional to its CSA
the resistance of a conductor is inversely proportional to its length and inversely proportional to its CSA
What term is used to describe the ability of a material to resist the flow of electric current?
resistance
resistivity
capacitive reactance
inductive reactance
If a conductor's resistance rises with temperature rise, what term is used?
negative temperature coefficient
positive temperature coefficient
temperature/resistance
'rising resistance'
If a conductor's resistance falls with temperature rise, what term is used?
negative temperature coefficient
positive temperature coefficient
temperature/resistance
'falling resistance'
Calculate the resistance of 50m of copper conductor with CSA = 4mm/sq. Take resistivity value as 1.78x10-8 ohms per metre
0.222 ohms
1.355 ohms
1.225 ohms
0.025 ohms
Determine the resistance of 100m of aluminium conductor. CSA is 120mm sq. Use resistivity of aluminium = 2.84x10-8 ohms m.
0.0237 ohms
0.0556 ohms
0.222 ohms
1.001 ohms
What is the unit of inductance?
Farad
Henry
Ohm
Coulomb
What effect does an inductor have on an AC circuit?
no effect
sets up opposing current
decreases its resistance
converts it to DC
What unit has the symbol 'B' ?
flux density
inductance
capacitance
inductive reactance
Which one of the following magnetism statements is not true ?
like poles repel
unlike poles attract
magnetic lines of force can touch each other
AC and DC can be used to make an electromagnet
What is the unit of capacitance?
ohm
Farad
henry
tesla
What safety must be acknowledged when working with capacitors ?