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In PMMC meter or (D'Arsonval) meter or galvanometer all are the same instrument, a
coil of fine wire is suspended in a magnetic field produced by permanent magnet. According to
the fundamental law of electromagnetic force, the coil will rotate in the magnetic field when it
carries an electric current by electromagnetic (EM) torque effect. A pointer which attached the
movable coil will deflect according to the amount of current to be measured which applied to the
coil. The (EM) torque is counterbalance by the mechanical torque of control springs attached to
the movable coil also. When the torques are balanced the moving coil will stopped and its angular
deflection represent the amount of electrical current to be measured against a fixed reference,
called a scale. If the permanent magnet field is uniform and the spring linear, then the pointer
deflection is also linear
What else can I help you with?
When does Tylenol start working after taking it?
Tylenol typically starts working within 30 minutes to 1 hour after taking it.
What is difference between stock and working solution?
A stock solution is a concentrated solution of a substance that is diluted to make working solutions of desired concentrations. A working solution is a solution ready for immediate use in an experiment or process. Stock solutions are typically stored for longer periods and used to prepare multiple working solutions.
Why did your pen suddenly stop working?
The pen may have stopped working due to a lack of ink, a clogged tip, or a mechanical issue with the pen.
Why do pens stop working?
Pens stop working when the ink inside dries up or clogs the tip, preventing it from flowing smoothly onto the paper.
What is the difference between hot and cold working?
The names say it all...Cold working is done cold, i.e. part at room temperature. It essentially pushed into something to deform it. This yields the part, technically increasing its yield for further use, but it will decrease the stress required to go from its new yield to its max tensile. Be advised, for very thick parts, like bars above 2", only the outer portions will cold work, the core will keep the same properties as un-worked metal.Hot working heats the part up above its recrystallization temperature so along with deformation, the part recrystallizes, thereby not cold working it. Hot working does not give a yield strength increase like cold working does.
What is pmmc type of instruments?
Produce of series type Ohmmeter using PMMC of Ifsd:100uA for range of 0-20kohm?
Why pmmc used for DC only?
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.
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.
Operation of PMMC instrument?
aku pon tatau
Is Series resistance and PMMC used as voltmeter?
yes
Why pmmc instrument have uniform scale?
PMMC instruments have a uniform scale because the deflection of the coil is directly proportional to the current passing through it. This linear relationship allows for precise measurement of small changes in current, making the scale consistent and uniform.
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
Differences between Permanent magnet moving coil and moving iron?
Permanent magnet moving coil (PMMC) instruments use a moving coil that is suspended between the poles of a permanent magnet, whereas moving iron instruments use a stationary coil and a moving iron piece that moves within the coil's magnetic field. PMMC instruments are more accurate but have limited range, while moving iron instruments are less accurate but can measure higher currents. PMMC instruments are inherently more expensive compared to moving iron instruments.
What are the similarities of PMMC and moving iron type measuring instruments?
Both PMMC (Permanent Magnet Moving Coil) and moving iron type measuring instruments are analog devices used for measuring electrical quantities. They both operate based on the interaction between magnetic fields and electric currents to produce a mechanical deflection for display. Additionally, they are both commonly used in applications where accuracy and precision are important factors.
What is pmmc?
pmmc stands for permanent magnet moving coil instruments these instruments are secondary measuring instruments in these instruments a permanent magnet is installed and a moving coil in this way when current is passed through the fixed coil then a force will be developed on the moving coil and thus it moves and with this moving pointer moves on the scale and gives the corresponding reading . if someone wants to read it thoroughly then he can try ashfaq hussain , j.b.gupta of basic elelctrical engg. for b.tech first year .
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.
How many types of plastics are there?
plastics are of 5 types[1]- polythene[2]- polyvinyl chloride (PVC)[3]- orion/polyvinyl cyanide /polyacryl nitrile (PAN)[4]- polymethyl meth acrylate (PMMC)[5]- polysterene
