# Past NTS Paper Solutions!



## WajeehBJ (Jul 8, 2011)

Alright, here is the thread and here goes my question. 

When a conductor of cross sectional area 5*10power6 m2 carries a current of 6A, the drift velocity of the conduction electrons is 1.2*10power4 ms-1. What is the number density (number per unit volume) of the conduction electrons:-
A= 4*10power-28 m-3
B= 1.6*10power-27 m-3
C= 2.5*10power27 m-3
D= 6.3*10power28 m-3
E= 1.3*10power34 m-3

Whoever knows the solution, kindly post here.


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## WajeehBJ (Jul 8, 2011)

BUMP

P.S you can post your own questions as well from the NTS last year entry test for Federal Medical and dental college.


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## Usman Ejaz (Feb 2, 2012)

I=nAqv
I think the answer is option D. i.e n=I/Aqv. You messed up the powers of drift velocity and the Area,they should be negative.


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