(Solved) A 1 kVA, single phase, 50 Hz, 100/250 V trarsformer gives the following results on short circuit test conducted at high voltage Side: voltmeter reading: 12.5 V, Ammeter reading: 4 A, Wattmeter reading: 80 W. The equivalent resistance referred to high voltage side will be

 Question : [GSECL JE ELECTRICAL] 

A 1 kVA, single phase, 50 Hz, 100/250 V trarsformer gives the following results on short circuit test conducted at high voltage Side: 

Voltmeter reading: 12.5 V, Ammeter reading: 4 A, Wattmeter reading: 80 W. 

The equivalent resistance referred to high voltage side will be____. 

ઉચ્ચ વોલ્ટેજ બાજુએ હાથ ધરાયેલ લઘુ પરિપથ પરીક્ષણ માટે 1 KVA, એકલચરણ, 50 Hz, 100/250 નું એક પરિવર્તક નીચે મુજબના પરિણામો આપે છે

વોલ્ટમીટર વાંચન: 12.5 V, એમીટર વાંચન: 4 A, વૉટમીટર વાંચન: 80 W. 

ઉચ્ચ વોલ્ટેજ બાજુએ સંદર્ભિત સમતુલ્ય અવરોધ _______ રહેશે.

(a) 20 ohm

(b) 5 ohm

(c) 40 ohm

(d) 10 ohm

Answer : (b) 5 ohm

To find resistance referred to high voltage side, we need short circuit test data only which is given in question. 

High voltage side resistance = Short circuit power/(current)²

Resistance referred to HV side = 80 W/ (4 A)²

Resistance referred to HV side = 5 ohm. 

Option (b) - correct.