The S.C. test on a 1-phase transformer, with the primary winding short-circuited and 30 V applied to the secondary gave a wattmeter reading of 60 W and secondary current of 10 A. II the normal applied primary voltage is 200 V, the transformation ratio 1:2 and the full-load secondary current 10 A, calculate the secondary p.d. at full-load current for (a) unity power factor (b) power factor 0.8 lagging.
these are the answers [ 394 V; 377.6 V ]
The S.C. test on a 1-phase transformer, with the primary winding short-circuited and 30 V applied...
A single-phase transformer is rated at 10 kVA, 240/100 V. When the secondary terminals are open-circuited and the primary winding is supplied at normal voltage, the input current is 2.6 A at a power factor of 0.3 lag. When the secondary terminals are short-circuited, a voltage of 18 V applied to the primary causes the full-load current to flow in the secondary, the power input to the primary being 240 W. Calculate (a) the regulation (b) the efficiency of the...
A 3-phase, 50 Hz, 6600 /1000 /440 Y V. transformer. 1. Determine suitable numbers of turns to ensure the peak flux does not exceed 0.03 Web. 2. Determine the...
Question: A 3-phase, 50 Hz, 6600 /1000 /440 Y V. transformer. (i) What is the purpose of using three winding transformers? (ii)Determine suitable numbers of turns to ensure the peak flux does not exceed 0.03 Web. (ii) Determine the primary line current and power factor if the 1000 V winding delivers a balanced load of 100 kVA at 0.8 power factor lagging and the 440 V winding delivers a balanced load of 50 kW at unity power factor.
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1. If 480 volts is applied to the primary winding of a transformer which has 300 turns in the primary winding and 15 turns in the secondary winding, the secondary voltage will be A. 0.0417 volts. C. 56.8 volts B. 24 volts. D. 9600 volts. 2. A distribution transformer with a grain-orientented steel core is highly efficent because its A. exciting current is sufficiently high. B. flux direction is parallel to the stell-rolling direction C. permeability is increased due to...