MCQs of Transformers (Electrical Machine - I - 3140913)

Electrical Machine - I (3140913) MCQs

MCQs of Transformers

Showing 131 to 140 out of 155 Questions

131.

A T − T transformer cannot be paralleled with ......... transformer.

(a)	V - V
(b)	Y − ∆
(c)	Y − Y
(d)	∆ − ∆

132.

A 150 kVA Scott transformer is connected with 440 V at the 3-φ side and getting 200 V at two 1-φ sides each. What will be the turns ratio of the teaser transformer.

(a)	0.45
(b)	0.52
(c)	2.2
(d)	1.90

133.

A T − T connection has a higher ratio of utilization that a V − V connection only when

(a)	identical transformers are used
(b)	load power factor is leading
(c)	load power factor is unity
(d)	non-identical transformers are used

134.

The biggest advantage of T - T connection over the V - V connection for 3-phase power transformation is that it provides

(a)	a set of balanced voltages under load
(b)	a true 3-phase, 4-wire system
(c)	a higher ratio of utilization
(d)	all of the above.

135.

Tap changer is generally provided in

(a)	Current transformer
(b)	Power Transformer
(c)	Voltage Transformer
(d)	Earthing transformer

136.

The tap changer in an electrical power transformer is provided on

(a)	Both LV and HV Winding
(b)	LV Winding
(c)	Either LV or HV Winding
(d)	HV Winding

137.

In an oil filled transformer, the application of oil is for

(a)	Cooling
(b)	Insulation
(c)	both cooling and insulation
(d)	preventing the accumulation of dust

138.

Transformer cooling and insulating oil must be of

(a)	low viscosity
(b)	high viscosity
(c)	low BDV
(d)	low resistivity

139.

The heat generated in the transformer is dissipated mainly by

(a)	Conduction
(b)	Convection
(c)	Radiation
(d)	all of the above

140.

The heat transfer by convection in a transformer least depends on

(a)	temperature difference
(b)	air velocity
(c)	surface area
(d)	color of the paint

Showing 131 to 140 out of 155 Questions