Question

There are 8.4 x 1022 free electrons per cm in
current in the wire is 0.21 A
(e = 1.6 x 10-19 C). Then the drifts velocity of
electrons in a copper wire of 1 mm2 cross section,
will be :-
(1) 2.12 x 10-6 m/s (2) 0.78 x 10-5 m/s
(3) 1.56 x 10-6 m/s (4) none of these

plss give the whole calculation ​

Answer 1

Answer:

4

Step-by-step explanation:

current, i equal to 1A

Area of cross -section A =

1 millimeters square = 1 ×

10 Ka power -6 meter square

length of the conductor = l

Also

Mass of copper wire = volume into density

m =A×L×P=》m=Al×9000

we know that the number of atoms in molecular mass, M=NA

therefore No. of atoms in mass, m,N= (NA/M )m

where NA is known as Avogadaro no. and is equal to 6×10 Ka power 23 =》N=(NA/M)m=》N=(NA/M)×A×l×9000

Also, it is given that

No. of free electron =No. of atom

Let n be the no. of free electron per unit volume

n=No. of electron/volume =NA×A×l×9000/M×A×like

NA×9000/m=6×10 Ka power 23/63.5× 10 Ka power -23

therefore i=VdnAe=》1/6×10ka power 23×9000/63.5×10ka power-3 ×10ka power-6×1.6×10 Ka power -19=63.5×10ka power-3/6×10 Ka power 23×9000×10ka power -6×1.6×10ka power -19=63.5×10ka power -3/6×10 Ka power 26×9×10ka power -6×1.6×10ka power -19=63.5×10ka power -3/6×9×16=0.073×10 Ka power -3 m/s=0.073 m/ s

so the answer is 4

Answer 2

Questions:

There are 8.4 x 10^22 free electrons per cm

3 in copper. The current in the wire is 0.21 A

(e 1.6 x 10-19 C). Then the drifts velocity of

electrons in a copper wire of 1 mm2 cross section.

will be :

Answer:

Option C