Advertisements
Advertisements
Question
Given the input current 15 A and the input voltage of 100 V for a step-up transformer having 90% efficiency, find the output power and the voltage in the secondary if the output current is 3 A.
Solution
\[\text { Input current } = 15 A\]
\[\text { Input voltage } = 100 V\]
\[efficiency = 90 % = 90/100\]
\[\frac{\text { Output power }}{\text { Input power}} = 0 . 9\]
\[\frac{\text { Output power }}{\text { Input voltage} \text { times Input current }} = \frac{\text { Output power}}{15 \times 100} = 0 . 9\]
\[\text { Output power} = 15 \times 100 \times 0 . 9 = 1350 W\]
\[\text { Outpur current} = 3 A\]
\[\text { Output voltage } = \frac{\text { Output power}}{\text { Output current}} = \frac{1350}{3} = 450 V\]
APPEARS IN
RELATED QUESTIONS
A transformer converts 240 V AC to 60 V AC. The secondary has 75 turns. The number of turns in primary are _______.
(A) 600
(B) 500
(C) 400
(D) 300
State the principle of the step-down transformer and its working.
The following diagram in Fig. 10.44 shows a coil X connected to a sensitive centre –zero galvanometer G and a coil P connected to a battery through a switch S.
(a) Describe the observation when the switch S is (i) closed suddenly, (ii) then kept closed, (iii) finally opened.
(b) Name and state the law which explains the above observations.
In a transformer, the frequency of A.C. voltage ______.
State the underlying principle of a transformer. How is the large scale transmission of electric energy over long distances done with the use of transformers?
State the principle of working of a transformer. Can a transformer be used to step up or step down a d.c. voltage? Justify your answer.
An ideal transformer has 100 turns in the primary and 250 turns in the secondary. The peak value of the AC is 28 V. The rms secondary voltage is nearest to ______
A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is
A power transmission line feeds input power at 2300 V to a stepdown transformer with its primary windings having 4000 turns. What should be the number of turns in the secondary in order to get output power at 230 V?
A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10 A, then the input voltage and current in the primary coil are ______.
