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GCAA Ghana AME Exam study materials
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GCAA Ghana AME Exam practice questions

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Question 1Mathematics and Physics

A dimension on a drawing is given as 3/4 inch. What is this length in millimetres, to two decimal places?

  1. 9.53 mm
  2. 19.05 mm Correct answer.
  3. 12.70 mm
  4. 25.40 mm

Explanation

One inch equals 25.4 mm, so the conversion is a single multiplication: 0.75 × 25.4 = 19.05 mm. Always multiply when converting from a larger unit (inch) to a smaller unit (millimetre).

Question 2Mathematics and Physics

A block of material has a mass of 2.7 kg and a volume of 1.0 × 10⁻³ m³. What is its density?

  1. 27 000 kg/m³
  2. 0.27 kg/m³
  3. 2700 kg/m³ Correct answer.
  4. 270 kg/m³

Explanation

Density is mass divided by volume: ρ = m/V = 2.7 ÷ 1.0 × 10⁻³ = 2700 kg/m³. The division by a small volume produces a large density value, which is typical of solid materials.

Question 3Mathematics and Physics

A 12 V supply is connected across a 4 Ω resistor. What current flows through the resistor?

  1. 0.33 A
  2. 8 A
  3. 3 A Correct answer.
  4. 48 A

Explanation

Ohm's law states I = V/R. Substituting gives 12 ÷ 4 = 3 A, so the current is 3 amperes.

Question 4Mathematics and Physics

A circular pipe has an internal diameter of 10 cm. What is its cross-sectional area?

  1. 15.7 cm²
  2. 78.5 cm² Correct answer.
  3. 314.0 cm²
  4. 31.4 cm²

Explanation

Area of a circle is πr². The radius is half the diameter, 5 cm, so A = π × 5² = 78.5 cm². Using the diameter directly in πr² gives an answer four times too large.

Question 5Mathematics and Physics

An aircraft accelerates uniformly from rest to 60 m/s in 12 s. What is its acceleration?

  1. 0.2 m/s²
  2. 5 m/s² Correct answer.
  3. 720 m/s²
  4. 2.5 m/s²

Explanation

For uniform acceleration, a = (v − u)/t. With u = 0, v = 60 m/s and t = 12 s, a = 60 ÷ 12 = 5 m/s².

Question 6Mathematics and Physics

A force of 250 N acts at right angles to a lever arm whose perpendicular distance from the pivot is 0.6 m. What is the moment about the pivot?

  1. 417 N·m
  2. 150 N·m Correct answer.
  3. 15 N·m
  4. 250.6 N·m

Explanation

Moment equals force multiplied by the perpendicular distance from the pivot: M = F × d = 250 × 0.6 = 150 N·m. The force must be perpendicular to the arm for this direct product to apply.

Question 7Mathematics and Physics

In a hydraulic system a force of 200 N is applied to a piston of area 0.002 m². The pressure is transmitted unchanged to a second piston of area 0.05 m². What force does the second piston exert?

  1. 200 N
  2. 50 000 N
  3. 5000 N Correct answer.
  4. 8 N

Explanation

Pascal's principle gives a common pressure: P = F/A = 200 ÷ 0.002 = 100 000 Pa. The output force is then P × A₂ = 100 000 × 0.05 = 5000 N.

Question 8Mathematics and Physics

A 28 V DC motor draws a current of 5 A. What is its electrical input power?

  1. 5.6 W
  2. 140 W Correct answer.
  3. 23 W
  4. 33 W

Explanation

Electrical power is the product of voltage and current: P = V × I = 28 × 5 = 140 W.

Question 9Mathematics and Physics

A fixed mass of gas occupies 3.0 L at a pressure of 200 kPa at constant temperature. It is compressed to 0.60 L. What is the new pressure?

  1. 1000 kPa Correct answer.
  2. 600 kPa
  3. 40 kPa
  4. 4000 kPa

Explanation

At constant temperature Boyle's law applies: P₁V₁ = P₂V₂. Rearranging gives P₂ = (200 × 3.0) ÷ 0.60 = 1000 kPa, so a fivefold reduction in volume raises pressure fivefold.

Question 10Mathematics and Physics

A tensile load of 5000 N acts on a rod with a cross-sectional area of 250 mm². What is the tensile stress in the rod?

  1. 50 MPa
  2. 0.05 MPa
  3. 20 MPa Correct answer.
  4. 1.25 MPa

Explanation

Stress is force divided by area: σ = F/A = 5000 ÷ 250 = 20 N/mm². Since 1 N/mm² equals 1 MPa, the stress is 20 MPa.

Question 11Mathematics and Physics

An aircraft climbs at a speed of 200 m/s along a flight path inclined at 30° above the horizontal. What is the horizontal component of its velocity?

  1. 115.5 m/s
  2. 173.2 m/s Correct answer.
  3. 100.0 m/s
  4. 200.0 m/s

Explanation

The horizontal component is found by resolving along the horizontal axis: vₕ = v cos θ = 200 × cos 30° = 200 × 0.866 = 173.2 m/s. The vertical component would use the sine of the angle.

Question 12Mathematics and Physics

An aluminium alloy rod is exactly 2.00 m long at 15 °C. The coefficient of linear expansion is 23 × 10⁻⁶ per °C. The rod warms to 65 °C. By how much does it lengthen?

  1. 2.3 mm Correct answer.
  2. 11.5 mm
  3. 0.46 mm
  4. 0.023 mm

Explanation

Linear expansion is ΔL = L α ΔT. Here ΔT = 50 °C, so ΔL = 2.00 × 23 × 10⁻⁶ × 50 = 2.3 × 10⁻³ m, which is 2.3 mm.

Question 13Electrical Fundamentals

A 28 V DC circuit has a total resistance of 7 ohms. What current flows in the circuit?

  1. 4 A Correct answer.
  2. 0.25 A
  3. 21 A
  4. 196 A

Explanation

Ohm's law relates voltage, current and resistance as V = I x R, so the current is found by dividing voltage by resistance. Here I = 28 / 7 = 4 A.

Question 14Electrical Fundamentals

In a series circuit containing three different resistors, which quantity has the same value through every component?

  1. Current Correct answer.
  2. Power
  3. Resistance
  4. Voltage

Explanation

A series circuit provides only one path for charge, so the same current must pass through every component in turn. The supply voltage divides between the resistors in proportion to their values, so voltage, resistance and power can all differ.

Question 15Electrical Fundamentals

A 2 microfarad capacitor is connected across a 50 V DC supply. How much charge does it store?

  1. 25 microcoulombs
  2. 0.04 microcoulombs
  3. 100 microcoulombs Correct answer.
  4. 200 microcoulombs

Explanation

The charge held by a capacitor is given by Q = C x V, with capacitance in farads and voltage in volts. Substituting gives 2 x 10^-6 F x 50 V = 1 x 10^-4 C, which is 100 microcoulombs.

Question 16Electrical Fundamentals

A 6 ohm resistor and a 3 ohm resistor are connected in parallel. What is the total resistance of the combination?

  1. 4.5 ohms
  2. 9 ohms
  3. 18 ohms
  4. 2 ohms Correct answer.

Explanation

For two resistors in parallel the total is the product divided by the sum: (6 x 3) / (6 + 3) = 18 / 9 = 2 ohms. The result is always smaller than the smallest individual resistance, which confirms the answer.

Question 17Electrical Fundamentals

A sinusoidal alternating voltage has a peak value of 100 V. What is its root mean square value?

  1. 70.7 V Correct answer.
  2. 141.4 V
  3. 63.7 V
  4. 50 V

Explanation

For a sine wave the RMS value equals the peak value divided by the square root of 2, that is 0.707 times the peak. Here 100 x 0.707 = 70.7 V.

Question 18Electrical Fundamentals

A transformer has 200 turns on its primary winding and 50 turns on its secondary. If the primary is supplied with 120 V AC, what voltage appears at the secondary?

  1. 60 V
  2. 30 V Correct answer.
  3. 15 V
  4. 480 V

Explanation

The voltage ratio of a transformer equals the turns ratio, so secondary voltage is primary voltage multiplied by secondary turns divided by primary turns. Here 120 x (50 / 200) = 120 / 4 = 30 V, a step-down result consistent with fewer secondary turns.

Question 19Electrical Fundamentals

At a junction in a circuit, 5 A flows in on one conductor and 2 A flows in on a second conductor. What current leaves the junction on the third conductor?

  1. 3 A
  2. 7 A Correct answer.
  3. 10 A
  4. 2.5 A

Explanation

Kirchhoff's current law states that the total current entering a junction equals the total current leaving it, because charge cannot accumulate at a point. The two incoming currents add to 5 + 2 = 7 A, so 7 A must leave.

Question 20Electrical Fundamentals

An inductor of 0.1 henry is connected to a 100 Hz AC supply. What is its inductive reactance?

  1. 62.8 ohms Correct answer.
  2. 628 ohms
  3. 10.0 ohms
  4. 31.4 ohms

Explanation

Inductive reactance is given by XL = 2 pi f L. Substituting f = 100 Hz and L = 0.1 H gives 2 x 3.14 x 100 x 0.1, which is approximately 62.8 ohms.

Question 21Electrical Fundamentals

A single phase AC motor draws 10 A from a 115 V supply while delivering 920 W of true power. What is the power factor of the motor?

  1. 0.80 Correct answer.
  2. 0.92
  3. 1.25
  4. 0.60

Explanation

Power factor is true power divided by apparent power, where apparent power is the product of voltage and current. Apparent power is 115 x 10 = 1150 VA, so the power factor is 920 / 1150 = 0.80.

Question 22Electrical Fundamentals

Two 12 V batteries, each with an internal resistance of 0.5 ohm, are connected in parallel and supply a 5.75 ohm load. What is the terminal voltage of the combination?

  1. 11.5 V Correct answer.
  2. 11.0 V
  3. 10.5 V
  4. 12.0 V

Explanation

Two equal internal resistances in parallel give 0.25 ohm, so the total circuit resistance is 0.25 + 5.75 = 6 ohms and the current is 12 / 6 = 2 A. The internal drop is then 2 x 0.25 = 0.5 V, leaving a terminal voltage of 12 - 0.5 = 11.5 V.

Question 23Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

In a forward-biased silicon PN junction diode, the typical voltage drop is approximately:

  1. 0.7 V Correct answer.
  2. 0.3 V
  3. 12 V
  4. 5.0 V

Explanation

A silicon diode begins to conduct appreciably at about 0.6 to 0.7 V forward bias, so 0.7 V is the usual working value. Germanium diodes are lower, around 0.3 V. The other values are far above a normal junction drop.

Question 24Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

Which logic gate produces a HIGH output only when every input is HIGH?

  1. NOR gate
  2. XOR gate
  3. AND gate Correct answer.
  4. OR gate

Explanation

The AND function gives output 1 only for the all-ones input combination. OR gives 1 when any input is 1, NOR is its inverse, and XOR gives 1 when the inputs differ.

Question 25Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

The binary number 1011 is equal to which decimal value?

  1. 11 Correct answer.
  2. 10
  3. 9
  4. 13

Explanation

Place values from right to left are 1, 2, 4 and 8. Adding 8 + 0 + 2 + 1 gives 11.

Question 26Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

An LED emits light when it is:

  1. operated as a zener diode
  2. forward-biased Correct answer.
  3. exposed to strong infrared light
  4. reverse-biased below breakdown

Explanation

In an LED, forward bias causes electrons and holes to recombine and release photons. Reverse bias does not produce normal light emission and can damage the device.

Question 27Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

The process of converting a continuously varying signal into a digital value is called:

  1. amplitude modulation
  2. digital-to-analogue conversion
  3. analogue-to-digital conversion Correct answer.
  4. full-wave rectification

Explanation

An ADC samples an analogue voltage and encodes it as a binary number. DAC performs the reverse, modulation shifts information onto a carrier, and rectification changes AC to pulsating DC.

Question 28Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

For an NPN bipolar transistor in the active region, the junction bias is:

  1. base-emitter forward-biased and collector-base reverse-biased Correct answer.
  2. both junctions forward-biased
  3. both junctions reverse-biased
  4. base-emitter reverse-biased and collector-base forward-biased

Explanation

Active-region operation requires the emitter junction to be forward-biased so carriers are injected, and the collector junction reverse-biased so they are collected. Both forward describes saturation; both reverse describes cutoff.

Question 29Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

An ideal operational amplifier is normally assumed to have:

  1. zero input impedance and very high output impedance
  2. infinite input impedance and zero output impedance Correct answer.
  3. infinite input and output impedance
  4. input impedance equal to output impedance

Explanation

An ideal op-amp draws no input current and can drive any load, so input impedance is infinite and output impedance is zero. Real devices approximate these values.

Question 30Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

A JK flip-flop has J = 1 and K = 1. On the next active clock edge it will:

  1. reset to 0
  2. toggle Correct answer.
  3. set to 1
  4. hold its state

Explanation

With both J and K HIGH, the JK flip-flop toggles, so the output becomes the complement of its previous state. J = 1, K = 0 sets; J = 0, K = 1 resets; J = K = 0 holds.

Question 31Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

A multiplexer is a circuit that:

  1. stores a single binary digit
  2. selects one input from several Correct answer.
  3. routes a single input to many outputs
  4. converts parallel data to serial form

Explanation

A multiplexer uses select lines to connect one of many inputs to a common output. The reverse operation, one input to many outputs, is demultiplexing.

Question 32Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

ARINC 429 is best described as:

  1. a bidirectional, multi-source parallel bus
  2. a parallel backplane bus
  3. a unidirectional serial bus Correct answer.
  4. a fibre-optic avionics bus

Explanation

ARINC 429 uses a single transmitter feeding one or more receivers over a twisted pair, so data flow is one-way on each bus. It is a serial, not parallel, avionics data bus.

Question 33Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

On an aircraft fitted with EICAS, engine parameters and crew alerts are normally shown:

  1. on the weather radar indicator screen only
  2. on dedicated engine and alerting displays Correct answer.
  3. only on the primary flight display
  4. on the standby flight instruments

Explanation

EICAS presents engine indications and caution or warning messages on dedicated displays in the flight deck. Primary flight displays show attitude, airspeed and similar flight data.

Question 34Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

A liquid crystal display forms an image by:

  1. rotating a tiny mirror
  2. changing light polarisation Correct answer.
  3. deflecting an electron beam
  4. emitting light from each pixel

Explanation

Liquid crystals twist under an applied electric field and change the polarisation of light passing through polarising filters. The pixel itself normally does not emit light; a backlight or reflector supplies the light.

Question 35Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

The Boolean expression A + A·B simplifies to:

  1. A + B
  2. A·B
  3. A Correct answer.
  4. B

Explanation

By the absorption law, A + A·B = A(1 + B) = A. The term A·B is already covered whenever A is true.

Question 36Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

A 4-bit serial-in, parallel-out shift register is clocked four times after new data is applied serially. The result is that the data:

  1. is lost at the next clock pulse
  2. remains serial at the input line
  3. appears in parallel on four outputs Correct answer.
  4. is converted to an analogue voltage

Explanation

After four shifts, the four input bits occupy the four internal stages and are presented simultaneously on the parallel outputs. A serial-in, parallel-out register performs serial-to-parallel conversion.

Question 37Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

The MIL-STD-1553 avionics data bus typically uses:

  1. a fibre-optic cable
  2. a parallel ribbon cable
  3. a twisted shielded pair Correct answer.
  4. a single-ended coaxial cable

Explanation

MIL-STD-1553 is a serial bus that uses a shielded twisted pair with Manchester II encoding and transformer coupling. It is not a parallel bus and is not inherently fibre-optic.

Question 38Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

A 10-bit ADC has a full-scale range of 5 V. Its resolution is approximately:

  1. 4.9 mV Correct answer.
  2. 1 V
  3. 0.1 V
  4. 20 mV

Explanation

A 10-bit converter has 2^10 = 1024 steps, so one least significant bit is about 5 V / 1024 = 4.88 mV. This is the smallest voltage change the ADC can distinguish.

Question 39Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

In a cathode ray tube display, the electron beam is moved across the screen by:

  1. a piezoelectric crystal element
  2. a liquid crystal layer
  3. an LED array
  4. magnetic deflection coils Correct answer.

Explanation

A CRT deflects the electron beam with magnetic fields from coils, or electrostatic plates in some tubes, to scan the phosphor screen. Liquid crystals and LEDs belong to other display technologies.

Question 40Electronic Fundamentals and Digital Techniques / Electronic Instrument Systems

In avionics digital data buses, a cyclic redundancy check (CRC) is used to:

  1. detect transmission errors Correct answer.
  2. increase the bit rate
  3. compensate for signal attenuation
  4. encrypt the data

Explanation

A CRC computes a check value from the data and appends it to the message; the receiver recomputes it and flags a mismatch as an error. It detects errors but does not correct attenuation, encrypt data, or change bus speed.

Question 41Materials and Hardware

In the aluminium alloy 2024, the principal alloying element added to aluminium is:

  1. Magnesium
  2. Manganese
  3. Zinc
  4. Copper Correct answer.

Explanation

2024 belongs to the 2000 series, in which copper is the main alloying addition; the copper-rich precipitates formed during heat treatment give the alloy its high strength. The other elements present, such as magnesium and manganese, are only minor additions.

Question 42Materials and Hardware

Alclad sheet consists of a heat-treated aluminium alloy core covered with a thin layer of commercially pure aluminium. The purpose of this coating is to:

  1. make the sheet easier to weld
  2. protect the core alloy by sacrificial action Correct answer.
  3. raise the ultimate tensile strength of the finished sheet
  4. improve the fatigue life of the sheet

Explanation

Commercially pure aluminium is anodic to the alloy core, so in a corrosive environment the cladding corrodes preferentially and protects the core from attack. The clad layer does not add strength and is removed from areas that must be joined by welding or riveting.

Question 43Materials and Hardware

A solid aluminium alloy rivet of 2117-T3 (AD) is identified on its manufactured head by:

  1. a raised cross on the head
  2. two dimples formed in the head
  3. a plain head with no marking
  4. one dimple on the head Correct answer.

Explanation

Standard aircraft rivets carry head markings that identify the alloy: 2117-T3 rivets are marked with a single dimple. The marking allows the mechanic to confirm the alloy before installation, since mixing rivet alloys can lead to corrosion or inadequate strength.

Question 44Materials and Hardware

In the bolt designation AN6-14, the number 6 identifies:

  1. the thread pitch in threads per inch
  2. the shank diameter in sixteenths of an inch Correct answer.
  3. the length of the bolt in eighths of an inch
  4. the grip length of the bolt

Explanation

In the AN bolt numbering system the first number is the nominal shank diameter in sixteenths of an inch, so an AN6 bolt is 6/16 inch or 3/8 inch in diameter. The dash number that follows gives the length in eighths of an inch.

Question 45Materials and Hardware

The function of lockwire on an aircraft fastener is to:

  1. seal the fastener against fluid leakage
  2. show that the fastener has been correctly torqued
  3. electrically bond the component to the structure
  4. prevent the fastener from loosening in service Correct answer.

Explanation

Lockwire is installed so that any tendency for a fastener to rotate loose is opposed by the wire pulling against a second fastener or anchor point. The wire is twisted in the tightening direction so that a loosening movement is resisted.

Question 46Materials and Hardware

After solution heat treatment and quenching, a 2024 aluminium alloy component develops its strength through:

  1. work hardening caused by cold working at room temperature
  2. precipitation of alloying elements during ageing Correct answer.
  3. rapid quenching in water
  4. annealing at an elevated temperature

Explanation

2024 is a precipitation-hardening alloy: quenching traps the alloying elements in supersaturated solid solution, and subsequent natural or artificial ageing precipitates fine particles that restrict dislocation movement. The quench itself does not strengthen the metal; it only prepares the structure for ageing.

Question 47Materials and Hardware

A magnesium alloy bracket is bolted directly to an aluminium alloy fuselage frame. In the presence of moisture, the part that corrodes preferentially is:

  1. the magnesium bracket, because it becomes anodic to aluminium Correct answer.
  2. the aluminium part, because aluminium becomes anodic to magnesium
  3. the steel bolt only, whatever its plating
  4. neither part, because both are light alloys

Explanation

In a galvanic couple the more anodic, less noble metal corrodes. Magnesium is anodic to aluminium, so the magnesium bracket becomes the anode and suffers preferential attack; the correct remedy is to separate the materials and protect the surfaces.

Question 48Materials and Hardware

In a cured fibreglass laminate, the resin matrix functions mainly to:

  1. carry the tensile loads imposed along the fibre direction
  2. determine the fatigue strength of the laminate
  3. bind the fibres together and transfer load between them Correct answer.
  4. provide stiffness in the fibre direction

Explanation

The resin holds the fibres in position, protects them from the environment and transfers load between adjacent fibres and plies through shear. The fibres themselves are the load-carrying members and give the laminate its strength and stiffness along their direction.

Question 49Materials and Hardware

Which of the following properties makes titanium alloys attractive for aircraft structural use?

  1. a low melting point combined with high thermal conductivity
  2. high strength-to-weight ratio and good corrosion resistance Correct answer.
  3. strong ferromagnetism at normal operating temperatures
  4. poor resistance to fatigue loading and to impact damage

Explanation

Titanium alloys combine high tensile strength with low density and excellent resistance to corrosion, and they retain useful strength at moderately elevated temperatures. Their main drawbacks are high cost and poor machinability, not a lack of strength or corrosion resistance.

Question 50Materials and Hardware

A spherical plain bearing is fitted at the end of an aircraft flight control push-pull rod. Its purpose is to:

  1. lock the linkage against rotation
  2. accommodate slight misalignment in the linkage Correct answer.
  3. carry heavy thrust loads inside a gearbox assembly
  4. reduce the weight of the control system

Explanation

The spherical inner ring allows angular movement between the rod and its attachment, so small misalignments and deflection of the structure do not induce bending loads in the rod. It also permits smooth oscillating motion without lubrication maintenance in many designs.