Transformer Principles in Aircraft Electrical Systems

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What happens when a magnet is suspended to swing freely?

It aligns itself with the earth's magnetic poles (correct)
It remains stationary and does not move
It changes its shape to conform to its surroundings
It aligns itself with the earth's gravitational poles

What is the function of the magnetic field surrounding a magnet?

It reduces the strength of the magnet
It arranges itself to conform to the shape of the magnet (correct)
It repels other magnets
It attracts other magnets

What is the primary principle behind the generation of AC voltage in a generator?

A conductor passing through lines of magnetic force (correct)
A coil rotating in a gravitational field
A stationary coil in a changing gravitational field
A magnet rotating in a stationary conductor

What determines the strength of the induced voltage in a generator?

The speed of the conductor and the strength of the magnetic field (D) Signup and view all the answers

What is the purpose of labeling the ends of a magnet as 'N' and 'S'?

To distinguish the north-seeking and south-seeking ends of the magnet (B) Signup and view all the answers

What is the earth's role in the behavior of magnets?

It is a giant magnet, with its poles attracting the ends of other magnets (B) Signup and view all the answers

What is a characteristic of a shunt DC motor?

Constant current through the field (A) Signup and view all the answers

Which type of DC motor is suitable for applications where constant speed is desired and high starting torque is not needed?

Shunt motor (C) Signup and view all the answers

What is the primary difference between a shunt and a series DC motor?

The connection of the field winding to the armature (C) Signup and view all the answers

What is the purpose of the series winding in a compound DC motor?

To provide a high starting torque (C) Signup and view all the answers

What is the characteristic of a compound DC motor's speed with load?

It varies less than in a series wound motor (C) Signup and view all the answers

What is the number of windings in the field of a compound DC motor?

Two (A) Signup and view all the answers

What is the relationship between the effective value and the peak value of an AC circuit?

The effective value is equal to 0.707 times the peak value. (C) Signup and view all the answers

Why are AC meters typically calibrated to display the effective value?

Because it is the approximate DC voltage of the same value. (A) Signup and view all the answers

What is the assumption made when a value is given for current or voltage in an AC circuit?

The value is always the effective value unless otherwise specified. (C) Signup and view all the answers

What is the purpose of specifying the effective value in AC circuits?

To provide a practical and useful measurement for AC circuits. (D) Signup and view all the answers

What is the relationship between the effective value and the heat produced in a resistor?

The effective value produces the same heat as the peak value. (A) Signup and view all the answers

What is the term used to describe the mathematical process of deriving the effective value?

Root mean square (RMS) value. (B) Signup and view all the answers

What is the primary purpose of a voltage transformer?

To step up or step down voltages (B) Signup and view all the answers

What is the primary difference between the primary windings of voltage and current transformers?

The connection method in the primary circuit (D) Signup and view all the answers

What is the name of the law that describes the current flow in the primary coil when voltage is applied?

Faraday's Law of Electromagnetic Induction (B) Signup and view all the answers

What is the primary function of the soft iron core in a transformer?

To form a path and concentrate the magnetic flux (A) Signup and view all the answers

What determines the strength of the magnetic field induced in a transformer?

The amount of current and number of turns in the winding (D) Signup and view all the answers

What is the name of the phenomenon that occurs when a current flows through the primary coil and sets up a magnetic field?

Mutual inductance (B) Signup and view all the answers

What is the characteristic of semiconductor materials?

Offering a resistance between the best conductors and insulators (B) Signup and view all the answers

Which of the following is a poor conductor of electricity?

Rubber (D) Signup and view all the answers

What is the relationship between the length of a wire and its resistance?

The longer the length, the greater the resistance (A) Signup and view all the answers

What happens to the resistance of a conductor when its cross-sectional area is doubled?

The resistance is reduced in half (B) Signup and view all the answers

What is the effect of temperature on the resistance of most conductors?

The resistance increases as temperature increases (D) Signup and view all the answers

Why does the resistance of a conductor decrease when its cross-sectional area is increased?

The electrons move without collision in the increased area (C) Signup and view all the answers