CPL General Aircraft Technical Knowledge practice exam.

Pascal's principle states that:

1. AThe static pressure of a moving fluid decreases as its velocity increases, which is the basis of the venturi
2. BThe volume of a fixed mass of gas is inversely proportional to its absolute pressure at constant temperature
3. CPressure applied to a confined fluid is transmitted undiminished in all directions and acts equally on equal areas
4. DA body immersed in a fluid experiences an upthrust equal to the weight of the fluid that the body displaces

Show the answer and why

Pressure applied to a confined fluid is transmitted undiminished in all directions and acts equally on equal areas

Because liquids are practically incompressible, a force applied to a piston in a closed hydraulic system raises the pressure throughout the fluid, and that pressure acts on every other piston in the system. This is the basis of hydraulic brakes, landing gear and flap systems. The other options describe Bernoulli's principle, Archimedes' principle and Boyle's law. Reference: syllabus 26.4.2; FAA-H-8083-31 Ch. 12.

The principle of electromagnetic induction is that:

1. AAn EMF is induced in a conductor whenever the magnetic flux linking it changes, its size depending on the rate of change
2. BA current flowing in one conductor always produces a steady voltage in a second conductor at rest in a steady field
3. CA stationary conductor in a steady magnetic field has a voltage induced in it proportional to the strength of the field
4. DA conductor becomes permanently magnetised whenever a voltage is applied across it for more than a few seconds

Show the answer and why

An EMF is induced in a conductor whenever the magnetic flux linking it changes, its size depending on the rate of change

Faraday's law: the induced EMF equals the rate of change of flux linkage, and Lenz's law says the induced current opposes the change producing it. Moving a conductor faster, using a stronger field, or more turns of wire increases the voltage. This principle is the basis of generators, alternators, magnetos, transformers, ignition coils and the tachometer generator. Reference: syllabus 26.2.28; FAA-H-8083-30 Ch. 12.

The relationship between horsepower and kilowatts is:

1. A1 horsepower equals 10 kW, so a 200 hp engine produces about 2000 kW at its rated speed
2. B1 kW equals 0.746 hp, so a 200 hp engine produces about 268 kW at its rated speed
3. C1 horsepower is about 0.746 kW, so 1 kW is about 1.34 hp; a 200 hp engine produces about 149 kW
4. D1 horsepower equals exactly 1 kW by international agreement, so a 200 hp engine produces 200 kW

Show the answer and why

1 horsepower is about 0.746 kW, so 1 kW is about 1.34 hp; a 200 hp engine produces about 149 kW

One horsepower is 550 foot-pounds per second, equal to 745.7 watts. New Zealand aircraft documents may quote either unit (a Lycoming IO-360 of 200 hp is 149 kW). Reference: syllabus 26.28.4; FAA-H-8083-30 Ch. 5.

Basic empty weight 1100 kg, pilot and passengers 250 kg, baggage 30 kg, fuel 180 kg at start; taxi fuel 5 kg; trip fuel burn 90 kg. The take-off weight and landing weight are:

1. ATake-off weight 1555 kg and landing weight 1555 kg, since the fuel burnt does not change the weight
2. BTake-off weight 1560 kg and landing weight 1380 kg, subtracting all the fuel for landing
3. CTake-off weight 1470 kg and landing weight 1380 kg, omitting the fuel from the take-off weight
4. DTake-off weight 1555 kg and landing weight 1465 kg

Show the answer and why

Take-off weight 1555 kg and landing weight 1465 kg

Ramp weight = 1100 + 250 + 30 + 180 = 1560 kg; take-off weight = ramp weight less taxi fuel = 1555 kg; landing weight = take-off weight less trip fuel = 1555 - 90 = 1465 kg. Each figure must then be compared with the applicable maximum (MCTOW, MCLW) and the CG checked at take-off and landing. Reference: syllabus 26.94.6(a),(b); FAA-H-8083-1 Ch. 4.