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In the Ohm'slaw experiment to find resistance of unknown resistor R following arrangements (a) and (b) are possible The resistance measured is given by R_(measured)=(V)/(i) V = voltage reading of voltmeter I = current Reading of ammeter But unfortunately the ammeters and voltmeter used are not ideal but having resistance R_(A) and R_(v) respect tively Yor are given two unknown resistors X and Y These resistances are to be determind using an ammeter of R_(A) = 0.5Omega and a voltmeter of R_(v) = 20kOmega It is known that X is in range of a few ohms and Y is in the range of several kilo ohm's Which circuit is perferable to measure X and Y {:("Resistor",Circuit),(x,(a)),(y,(b)):} . |
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Answer» `xrarr(a),yrarr(b)` Then measured RESISTANCE from arrangment (a) will be `R_(measured) = R + R_(A) ~~R` So (a) will be perferred if `R` is very small (~few Ohm) then measured resistance from (b) will be `R_(measured) = (R)/(1+(R)/(R_(v)))` where `R//R_(v)` is NEGLIGIBLE `so R_(measured)RARR R` So (b) will be perferred . |
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