Free UK Part-66 Module 3 Electrical Fundamentals — B1.1 Practice Questions

Sample Practice Questions

Try these 10 sample questions from the UK Part-66 Module 3 Electrical Fundamentals — B1.1 practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1Which particle carries the positive charge in an atom?

   1. A.ProtonCorrect answer: A
   2. B.Electron
   3. C.Neutron
   4. D.Molecule

   Explanation: The FAA handbook states: "Protons are positively-charged particles, and neutrons are neutrally-charged particles." The proton is positive; electrons are negative, neutrons neutral, and a molecule is a collection of atoms.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-1

2. 2A charge of 12 coulombs passes a point in 3 seconds. What is the average current?

   1. A.0.25 A
   2. B.9 A
   3. C.4 ACorrect answer: C
   4. D.36 A

   Explanation: The FAA handbook states: "Current is a measurement of a rate at which a charge flows through some region of space or a conductor." I=Q/t=12 C/3 s=4 A. Multiplication gives 36, reversing division gives 0.25, and subtraction gives 9; none computes charge per unit time.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-16

3. 3What distinguishes a secondary cell from a primary cell?

   1. A.Its discharge reaction can be reversed by chargingCorrect answer: A
   2. B.Its discharge reaction consumes material irreversibly
   3. C.Its normal discharge requires continuous external power
   4. D.Its discharge reverses automatically without energy input

   Explanation: The FAA handbook states: "A secondary cell is any kind of electrolytic cell in which the electrochemical reaction that releases energy is reversible." A secondary cell has reversible electrochemistry with energy supplied during charging. Irreversible primary-cell consumption, powered discharge and spontaneous recharge do not define it.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-87

4. 4A wire is replaced by one of the same material at the same temperature, with twice the length and twice the cross-sectional area. How does its resistance change?

   1. A.It halves
   2. B.It quadruples
   3. C.It remains the sameCorrect answer: C
   4. D.It doubles

   Explanation: The FAA handbook states: "The resistance of a metallic conductor is directly proportional to its length." The source also states resistance is inversely proportional to cross-sectional area. R scales by 2/2=1. Doubling or halving ignores one change; quadrupling applies area in the wrong sense. It also states: "The resistance of a metallic conductor is inversely proportional to the cross-sectional area."

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-18

5. 5A parallel-plate capacitor has its plate spacing halved, with plate area and dielectric unchanged. What happens to its capacitance?

   1. A.Twice its original capacitanceCorrect answer: A
   2. B.Half its original capacitance
   3. C.Four times its original capacitance
   4. D.Its original capacitance without change

   Explanation: The FAA handbook states: "The capacitance of parallel plates is inversely proportional to their spacing." C is inversely proportional to spacing, so Cnew/Cold=1/(1/2)=2. The alternatives use direct proportionality, a square dependence, or ignore spacing.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-51

6. 6A bar magnet is cut into two pieces. What magnetic poles does each piece have?

   1. A.Only a south pole
   2. B.No magnetic poles after cutting
   3. C.Both a north pole and a south poleCorrect answer: C
   4. D.Only a north pole

   Explanation: The FAA handbook states: "each piece immediately becomes a magnet itself, with a North and South pole." Cutting produces smaller dipoles, not isolated poles or automatically unmagnetised pieces.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-9

7. 7What is the function of the commutator in a basic DC generator?

   1. A.Keep external current alternating as coil voltage reverses
   2. B.Prevent voltage induction in the rotating armature
   3. C.Replace the need for a magnetic field in the generator
   4. D.Keep external current unidirectional as coil voltage reversesCorrect answer: D

   Explanation: The FAA handbook states: "commutator action causes the current to flow always in the same direction through the external circuit or meter." Commutation switches coil connections to give unidirectional external current. It neither prevents induction nor replaces the field, and alternating output is not its DC function.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-127

8. 8In an ideal purely inductive AC circuit, how does current relate in phase to voltage?

   1. A.Current is 180° from voltage
   2. B.Current lags voltage by 90°Correct answer: B
   3. C.Current leads voltage by 90°
   4. D.Current is in phase with voltage

   Explanation: The FAA handbook states: "In a circuit containing only inductance, the current reaches a maximum value later than the voltage, lagging the voltage by 90°" Pure inductance gives a quarter-cycle current lag. Leading describes capacitance, in-phase resistance, and 180° is not this reactive relationship.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-56

9. 9A basic RC filter must pass slowly varying signals and attenuate higher-frequency noise. Which connection should be used?

   1. A.Resistor in series, capacitor across the loadCorrect answer: A
   2. B.Capacitor in series, resistor across the load
   3. C.Series resistor and capacitor, output across both components
   4. D.Capacitor bypassed by a wire, output across that wire

   Explanation: The FAA handbook states: "a capacitive low-pass filter inserts a resistor in series and a capacitor in parallel with the load." The shunt capacitor's falling reactance at higher frequencies attenuates the output. A series capacitor with shunt resistance is high-pass; output across both series components reproduces the input, and output across a shorting wire is zero.

   Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-112

10. 10In normal synchronised operation, how does a synchronous motor rotor's speed compare with its stator's rotating magnetic field?

    1. A.It is half the field speed regardless of pole count
    2. B.It is equal to the field speedCorrect answer: B
    3. C.It is always slightly below the field speed
    4. D.It is always slightly above the field speed

    Explanation: The FAA handbook states: "the rotor is dragged along and rotates at the same speed as the rotating magnetic field produced by the stator windings." The synchronous rotor locks to field speed. A small speed difference is needed for induction-motor torque, not normal synchronous operation.

    Reference: FAA Aviation Maintenance Technician Handbook—General — Chapter 12, p. 12-151