Electrical Engineering - Inductors - Discussion

Discussion Forum : Inductors - General Questions (Q.No. 8)
8.
An ohmmeter is connected across an inductor and the pointer indicates zero ohms. The inductor is
good
open
shorted
partly shorted
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
19 comments Page 1 of 2.

SrEngineer said:   1 decade ago
An ohmmeter measures resistance, not impedance. An inductor is just a length of wire wound around a coil. At DC the resistance will be zero for an ideal inductor or very low for a real inductor. So you can't tell if this is a short or a high-q inductor. Suppose I measure a wire that is 1 foot long and it measures zero Ohms. Then I make 1 turn to make and inductor. The ohmmeter will still measure the same. So you can't tell if it is a good inductor or shorted one.

This statement from @Humar above is entirely wrong:

"If the inductor is shorted, inductor will offers zero impedance to current hence the current will not pass through the ohmmeter which has a resistance in it. Hence the pointer will not operate at that condition".

The truth is this:

If the inductor is shorted, inductor will offer zero impedance to current hence AS MUCH CURRENT AS POSSIBLE will flow through the ohmmeter, indicating the that the resistance is zero.

Zero impedance means maximum current not minimum current.

Satish kumar said:   1 decade ago
Ans:C.(shorted)
if the inductor is shorted, inductor will offers zero impedance to current hence the current will not pass through the ohmmeter which has a resistance in it.hence the pointer will not operate at that condition

Ashok & Balaji said:   1 decade ago
If the inductor is shorted, inductor will offers zero impedance to current hence the current will not pass through the ohmmeter which has a resistance in it. Hence the pointer will not operate at that condition.

Vikram said:   1 decade ago
If the inductor is shorted, inductor will offers zero impedance to current hence the current will not pass through the ohmmeter which has a resistance in it. Hence the pointer will not operate at that condition.

Venkatesh R said:   1 decade ago
To the best of my knowledge. It analog meter it the inductor reads short its good one not shorted. If you read in digital meter you can see 5 to 10 ohms.

So the correct answer is inductor is good one.

Sunil kumar said:   10 years ago
Ohmmeter reads resistance not impedance if there is no resistance then it must be a good inductor. So I think both (A) and (C) are correct.

But if we have to choose only one then (C) is better one.

Girisha P N said:   1 decade ago
Its simple question. When the pointer inducts 0 means the current goes to infinite value its happens only when the circuit s shorted (rejection of load and its shorted).

Prashant singh said:   1 decade ago
Of course ohmeter read zero. But it is impossible as every conductor has resistance. So we could say it is ideal inductor.

Ankur said:   1 decade ago
Here no mentioned the inductor is ideal or not. So we have to consider its practical aspects. So answer is (C) shorted.

Harish said:   1 decade ago
When it is open condition it shows infinity. If it is showing zero means motor is bad condition.


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