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Because in the coil DC current follow easly and pmmc meter is making with coil and AC current is not follow in coil so we used the pmmc only fpr DC current.
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∙ 13y ago
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Is Series resistance and PMMC used as voltmeter?
yes
Does the galvanometer measures AC and DC current?
It is used to detect very small DC currents only. For AC signals Detectors are used.
Do step up and down transformer only work with ac power or can you use them in dc only?
AC only. That's one of many reasons why AC is more useful (and more widely used!) than DC.
Where would DC be used instead of AC?
DC is used for extra-high voltage transmission systems, as there are less losses with DC than with AC, and no synchronising problems.
What device used to increase or decrease DC voltage?
A DC-to-DC converter is the general term for a device that changes DC voltage at one level to another.
Why pmmc instrument measure only ac not dc?
Permanent magnet moving coil instruments are used for measuring d.c. quantities only. This is so because for these instruments the torque is proportional to the operating quantity either voltage or current.
Is Series resistance and PMMC used as voltmeter?
yes
Why pmmc instrument is cannot be used to measure ac?
Pmmc meter are most accurate instrument for DC measurement however they are unable to measure the AC quantity. The working principle is as follows: a moving coil is free to move in a external static magnetic field. And the pointer moves according to the interaction of two fields, field of static mag. and that of measuring quantity. Now in case of it is impossible to produce a sustained magnetic field, that's why we can not use PMMC to measure the ac.
What is the explanation for the mechanism of DC in pmmc?
a pmmc has a coil suspended in permanent magnetic field.acording to the laws of electromagnetism a current carrying coil susspended in a magnetic field experiences an electromagnetic torque.This torque is counterbalanced by the mechanical torque devoloped in the coil in equlibrium.The angle teta can be measured and it is calibrated to directly give the current
Why dc source is used for dc supply?
it is only work on it so that used
What is pmmc type of instruments?
Produce of series type Ohmmeter using PMMC of Ifsd:100uA for range of 0-20kohm?
Operation of PMMC instrument?
aku pon tatau
Can you use transformer for DC supply?
No. Only Transformer could not be used for DC supply.If yoy need to have DC out put,then rectifier unit required .
Does the galvanometer measures AC and DC current?
It is used to detect very small DC currents only. For AC signals Detectors are used.
Can you run a 220 volt 1 horse motor with batteries?
batteries are only used for DC CIRCUTS. if the motor is a DC MOTOR you can.
Are diodes only used in a dc circuit?
There are lots of diodes - a "diode" is simply a device that has two electrical connections.If you refer specifically to the rectifying diode, it is used to convert AC current to DC current - so, it is used in a circuit that has BOTH AC and DC.
Why electronics device work only in dc?
Obviously you have not yet begun the AC circuit analysis class. Wait a few quarters.Some components are normally used with DC, some components are normally used with AC, but most components can be used with both DC and AC.
