GOTW: Sciene and tech game - Page 8

This question combines following topics:-

Originally posted by: rajnish_here

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next question-

what is stepper motor and how it works??

Originally posted by: its me tan

my question is:

in transformers, what is teh shape size and type of magnetic material used? why?

Originally posted by: akhl

Meanwhile let me ask one question: -

You are standing on a scale, which measures weight. The scale shows your correct weight. There is a cupboard nearby. You keep your palms on the top of the cupboard and push the cupboard down, which means that you apply downward force.

Will the scale show the same reading or less or more? Explain.

Answer this question correctly and earn points.😊

very nice question avinash... well time to loose marks but i will try
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lets analyse-
the weight measuring machine measures weight according to normal reaction on its surface. if we stand on it then normal reaction would be equal to weight. but if we push the cupboard down, there is some lift of the body which means normal reaction at the surface of weight measuring machine decrease as a result the weight measuring machine will measures less weight
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question from my side-
convert 107.50 (decimal) into Boolean, hexadecimal , octal numbers

@tan and avinash- PLease give marks as i have to finalize the result😊

Originally posted by: bhopalyellow

the magnetic material used in transformer is soft iron core.it is used in thin laminated iron core form.

the induced e.m.f. developed in the iron core produces current in the core in the form of closed loopes .which is called eddy currents.but the resistance of of iron core is small and the magnitude of eddy current is large so the large amount of energy produce may damage the insulation of copper windings .

to avoid it a laminated iron core is used in transformer which is prepared by joining similar iron strips, so the induced e.m.f. will will produce eddy currents in each ring seperately....as the iron strips is quite thin and posses very large resistance, the magnitude of eddy currents produced is quite small and hence only a small amount of heat is produced.😊

Originally posted by: its me tan

ok, a stepped motor is a 3 ph ac motor, where an internal rotor containing permanent magnets or a large iron core with salient poles is controlled by a set of external magnets that are switched electronically.

a stepped motor is very close to the design of that of synchronous motor( synchronous motors normally do not exist or are not built coz we need synchronous generators)

it consists of a no of coils in solenoid, as each coil is energised, the rotor aligns itself with the magnetic field produced by the enegised field winding. as the rotor aligs with each energised coil, it does nto move continuously, it rotates one step as each succeding coil is energised or de energised.

interested people can see and learn more by googling it, its mailny uded for step related activities where a continuous rotation is not required but position sequence is required. for example we use stepper motors largely in position controls as they r easy to handle and control ,

control guys know, stepper motors are operated in open loop and so controlling a stepper motor is easier than closed loop mechanisms of speed and postion control

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my question is:

in transformers, what is teh shape size and type of magnetic material used? why?

excelent 5 points to you😛

Rajnish,

Originally posted by: akhl

Rajnish,

Your answer is correct. So 5 points.

😲😲😲 its correct... i had doubt in this que... i also asked my friends some said this some that... so i analyzed my view and answered and its correct😛
😲

Yes your answer is correct.😊