The secondary coil of a transformer has 1500 turns and 10Ohm resistance. The primary coil has 1kOhm resistance. How many turns does the primary coil have?
- 15,000.
- 1,500,000.
- 150,000
Explanation
Impedance transforms as the square of the turns ratio, so Np/Ns equals the square root of the impedance ratio. Here that is the square root of 1000/10, which is the square root of 100, equal to 10. The primary therefore has 10 x 1500 = 15,000 turns. The much larger options come from squaring the ratio instead of taking its root.
Faiz0108 asking:
How does the answer comes to 15000?
Community Comments (4)
D
dimky Posts: 514 19.07.2013 / 21:09
Hey!
turn ratio = square_root(impendance ratio)
turn ratio = square_root(impendance ratio)
T
tsukiyo92 Posts: 13 31.07.2014 / 17:36
Then it should write 10 ohm IMPEDANCE instead of resistance ? its kind of misleading.
T
ta2x Posts: 3 14.04.2019 / 11:43
square_root(1000/10)=10*1500=15000 turns primary
F
Fabioscotto Posts: 1 25.09.2019 / 16:49
The O of Ohm seems lile a 0
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