SINGLE PHASE TRANSFORMER

The size of a transformer core will depend on

• (a) frequency

• (b) frequency and area of the core

• (c) flux density of the core material.

A shell-type transformer has

• (a) high eddy current losses

• (b) reduced magnetic leakage

• (c) negligibly hysteresis losses

• (d) none of the above

If ∅_m is the maximum value of flux in the core then the average rate of change of flux is

• a. f∅_m

• b. 2 f∅_m

• c. 4 f∅_m

• d. 4.44 f∅_m

If the supply frequency of a transformer increases, the secondary output voltage of the transformer

• Increase

• Decrease

• Remain the same

• NONE OF THE ABOVE

Lamination of the transformer core is made of

• Cast Iron

• Silicon Steel

• Aluminum

• Cast Steel

A transformer transform

• Current

• Voltage & current

• Frequency

• Voltage

A Step-Up Transformer which has 110/220 turns.What would happen if we replace it with 10/20 turns? (because Turns ratio would be same in both cases)

• induced E.M.F wold be same

• Induced E.M.F would be decreased

• Induced E.M.F would be increased

• None of the above

The rating of transformer may be expressed in ____________.

• kW

• KVA

• KVAR

• HORSE POWER

What will happen if the primary of a transformer is connected to D.C supply?

• Transformer will operate with low efficiency

• Transformer will operate with high efficiency

• No effect

• Transformer may start to smoke and burn

A Step Up transformer _____________.

• Step Up the level of Voltage

• Step down the level of current

• Step up level the power

• Step up the level of Frequency

• 1 and 2 only