Question

4) 3.2 x 10-ms!
0. A wire of 58cm long 2mm diameter carries
750mA current when 22mV potential
difference is applied at ends. If drift speed
of e is found 1.7x10 m/s then
1) Current density is 2.4x10ʻAlm
2) Current density is 1.6x104 Alm?
3) Number of free electrons per unit volume is
2
-3
2.7x10m
4) number of free electrons per unit volume
12.8x1025m3
time in a wire is if​

Answer 1

Answer:

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Answer 2

Answer:

given = length= 58cm

           diameter= 2mm r= 1mm

           current = 750 mA

           potential = 22 mV

           drift speed = 1.7X 10m/s

           

to find = current density

solution =  

  current density = J = I/A =  750X 10⁻³ /A

  J=  current density

  I = current

  A = area

for finding area , use the formula πr²= 3.14 X 10⁻⁶m²

now find the current density,

               J = 750 X 10⁻³/ 3.14 X 10⁻⁶  

               J = 2.4 X 10⁻⁵A/m²

    the current density is  2.4 X 10⁻⁵A/m²