A solenoid of length 0.700m having a circular cross-section of radius 5.00cm stores 6.00 μJ of energy when a 0.400-A current runs through it.

What is the winding density of the solenoid? (μ0 = 4π*10-7 T*m/A)

A) 865 turns/m

B) 327 turns/m

C) 1080 turns/m

D) 104 turns/m

E) 472 turns/m

Respuesta :

Answer:

The winding density of the solenoid, n = 104 turns/m

Explanation:

Given that,

Length of the solenoid, l = 0.7 m

Radius of the circular cross section, r = 5 cm = 0.05 m

Energy stored in the solenoid, [tex]E=6\ \mu J=6\times 10^{-6}\ J[/tex]

Current, I = 0.4 A

To find,

The  winding density of the solenoid.

Solution,

The expression for the energy stored in the solenoid is given by :

[tex]U=\dfrac{1}{2}LI^2[/tex]

Where

L is the self inductance of the solenoid

[tex]L=\mu_on^2lA[/tex]

n is the winding density of the solenoid

[tex]n=\sqrt{\dfrac{2U}{\mu_oI^2l\pi r^2}}[/tex]

[tex]n=\sqrt{\dfrac{2\times 6\times 10^{-6}}{4\pi \times 10^{-7}\times 0.7\times (0.4)^2\pi (0.05)^2}}[/tex]

n = 104 turns/m

So, the winding density of the solenoid is 104 turns/m

Answer

The winding density of the solenoid is 104 turns/m.

(D) is correct option.

Explanation:

Given that,

Length = 0.700 m

Radius = 5.00 cm

Energy = 6.00 μJ

Current = 0.400 A

We need to calculate the density of the solenoid

Using formula of the energy store

[tex]E=\dfrac{B^2}{2\mu_{0}}Al[/tex]

Put the value of magnetic field

[tex]E=\dfrac{(\mu_{0}ni)^2}{2\mu_{0}}Al[/tex]

[tex]n=\sqrt(\dfrac{2E}{\mu_{0}i^2Al})[/tex]

Put the value into the formula

[tex]n=\sqrt{\dfrac{2\times6.00\times10^{-6}}{4\pi\times10^{-7}\times(0.4)^2\times\pi\times(5.00\times10^{-2})^2\times0.700}}[/tex]

[tex]n=104\ turns/m[/tex]

Hence, The winding density of the solenoid is 104 turns/m.