ECNT

In a given transformer for given applied voltage, which of the following losses remain constant irrespective of load changes?

• Friction and windage losses

• Copper losses

• Hysteresis and eddy current losses

• Dielectric losses

Which of the following losses in a transformer is primarily dependent on the load current?

• Core losses

• Hysteresis losses

• Copper losses

• Friction and windage losses

In a transformer, what type of loss is caused by the magnetic properties of the core material?

• Hysteresis and eddy current losses

• Stray losses

• Copper losses

• Dielectric losses

Silicon steel used in laminations, because it reduces ________________

• Hysteresis loss

• Copper loss

• Dielectric losses
• b) Eddy current losses

Answer explanation

Electrical steels are also known as lamination steel or silicon steel. The main special thing related to the silicon steel is, its magnetic properties such as small hysteresis area and hence, small energy dissipation per cycle, thus low core loss.

A shell-type transformer has __________

• High eddy current losses
  

• Reduced magnetic leakage
  

• 
  Negligible hysteresis losses

• 
  Cannot be determined

Answer explanation

Since windings are brought closer in shell type compare to core type transformer, leakage of flux is very less in shell type transformer. Most of the flux gets linked with both of the coils though there is some leakage which can’t be avoided.

In a transformer, which component is responsible for inducing a voltage in the secondary coil?

• Magnetic core

• Primary coil

• Voltage regulator

• Secondary coil

Why is it important to insulate the primary and secondary coils in a transformer?

• To reduce the cost of production

• To make the coils more visible

• To increase the weight of the transformer

• To prevent electrical leakage, ensure safety, and improve efficiency.

What is the core of a transformer usually made of?

• Steel plates

• Aluminum foil

• Laminated iron sheets

• Copper wire

What is the efficiency of an ideal transformer?

• 100%

• 90%

• 75%

• 50%

A transformer is a _____ device.

• static

• Dynamic

• ststic and dynamic

• none