Question
A transformer has 1000 turns in the primary and 100 in
the secondary coil. If input voltage is 220 V, output voltage is:Solution
Transformers work on the principle: Vs/ Vp = Ns /Np. Substituting, Vs =100/1000 × 220 = 22V. Since fewer turns in the secondary, it's a step-down transformer.
A is 6 years older than B who is four times as old as C. The total sum of the ages of A, B and C is 60. How old is B?
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When 15 years is subtracted from the present age of A and the obtained result is divided by 4, then the present age of his nephew is obtained. If the pr...
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Present age of ‘P’ is 60% more than that of ‘Q’. 8 years ago, ‘P’ was twice as old as ‘Q’. Find the present age of ‘Q’.
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Five years ago from now, age of 'A' was ____ years. Ratio of present ages of 'A' and 'B' is ____ respectively and three years hence from now, sum of ag...
The ratio of ages of A, B and C is 2 : 4 : 5 and sum of their ages is 77. Find the ratio of A's age to B's age ten years hence.
7 years ago from now, the average age of ‘M’ and ‘N’ was 27 years. The ratio of present age of ‘M’ and ‘O’ is 3:5, respectively. If ‘...
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