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Physics MCQs thread.

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arlery said:
^ I'm confused. Can some one please explain this again?



volume = (22/7) x r^2 x l

now wire x and wire y have same volume so by using the formula of volume we can deduce that in increasing the length of wire Y by factor of 4 the area also decreases by factor of 4

so resistance of y = (resistivity) x 4l / (A/4) it becomes 16(resistivity)x l/A
R of X = (resistivity) x l/A
so the ratio would be 16!!!

Hope you get it!!!
 
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^ No I didn't mean this question, I meant the time base setting one on page 72.
 
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its C i guess coz the material is same so resistivity is same..and they both have same area and length is also x for both
 
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Guys can any one answer this question for me please.!!!

i know its easy but i don't know what i am missing.

the answer in marking scheme is A but i think it should be D

if it is A than combined resistance of 3 resistor should be 12. i dont know what to say
 

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the combined resistance is 2...so current n circuit = 12/(2+2)=3...now the current is divided in the ratio 1:2 between 6 ohm and 3 ohm resistor,,,hence I=1
 
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