Quiz 1 CP23

The working principle of a transformer is based on:

• Ohm's Law

• Electromagnetic induction

• Coulomb's Law

• Kirchhoff's Law

In a transformer, energy is transferred from primary to secondary through:

• Electric conduction

• Magnetic coupling

• Mechanical coupling

• Inductive coupling

Which part of the transformer provides mechanical support to the winding?

• Core

• Insulation

• Tank

• Bushings

The type of transformer used for measuring current in high-voltage circuits is:

• Power transformer

• Distribution transformer

• Current transformer

• Potential transformer

The EMF equation of a transformer is:

• E1= 4.44 f N1 ᶲm

• E2 = 4.44 f N2 Bm

• E1 = 4.44 f N2 Bm A

• E2/E1 = N1/N2

The induced EMF in the primary and secondary windings of a transformer depends on:

• Core material only

• Number of turns only

• Magnetic flux and number of turns

• Voltage applied

The voltage transformation ratio (K) of a transformer is defined as:

• V2/V1

• N2/N1

• E2/E1

• All of the above

For a step-up transformer, the transformation ratio is:

• Less than 1

• Equal to 1

• Greater than 1

• Zero

Core losses in a transformer are due to:

• Resistance of windings

• Eddy currents and hysteresis

• Load variations

• Stray capacitance

The efficiency of a transformer is maximum when:

• Copper loss equals iron loss

• Iron loss is minimized

• Load current is maximum

• Voltage regulation is maximum