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2 years ago

A long, straight, cylindrical wire of radius R carries a current uniformly distributed over its cross section.

Physics

1 answer:

Mice21 [21]2 years ago

3 0

Answer:

Explanation:

We shall solve this question with the help of Ampere's circuital law.

Ampere's ,law

∫ B dl = μ₀ I , B is magnetic field at distance x from the axis within wire

we shall find magnetic field at distance x . current enclosed in the area of circle of radius x

= I x π x² / π R²

= I x² / R²

B x 2π x = μ₀ x current enclosed

B x 2π x = μ₀ x I x² / R²

B = μ₀ I x / 2π R²

Maximum magnetic B₀ field will be when x = R

B₀ = μ₀I / 2π R

Given

B = B₀ / 3

μ₀ I x / 2π R² = μ₀I / 2π R x 3

x = R / 3

b ) The largest value of magnetic field is on the surface of wire

B₀ = μ₀I / 2π R

At distance x outside , let magnetic field be B

Applying Ampere's circuital law

∫ B dl = μ₀ I

B x 2π x = μ₀ I

B = μ₀ I / 2π x

Given B = B₀ / 3

μ₀ I / 2π x = μ₀I / 2π R x 3

x = 3R .

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Which of the following was an effect of the French Revolution?

lozanna [386]

Answer: C. the elimination of special privileges for members of the first and second estates

Explanation:

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From the options given, the effect of the French Revolution was the the elimination of special privileges for members of the first and second estates. Therefore, the correct option is C.

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3 years ago

The USDA recommends that women consume about 2000 Calories per day and men consume about 2500 Calories per day. How much average

professor190 [17]

Answer:

1500 W to 2200 W

Explanation:

Every person does work in his daily day to day life. A person needs energy in order to perform work. And the energy consumed by an individual while performing a daily work is directly responsible to the mount of oxygen consumed by the person.

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Accordingly, the average power required by a human body for doing regular work is in the range of 1500 W to 2200 W.

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2 years ago

A 2.0-cm-diameter parallel-plate capacitor with a spacing of 0.50 mm is charged to 200 V. What are (a) the total energy stored i

Debora [2.8K]

Answer:

(A) Total energy will be equal to $0.044\times 10^{-5}J$

(b) Energy density will be equal to $0.0175J/m^3$

Explanation:

We have given diameter of the plate d = 2 cm = 0.02 m

So area of the plate $A=\pi r^2=3.14\times 0.02^2=0.001256m^2$

Distance between the plates d = 0.50 mm = $0.50\times 10^{-3}m$

Permitivity of free space $\epsilon _0=8.85\times 10^{-12}F/m$

Potential difference V =200 volt

Capacitance between the plate is equal to $C=\frac{\epsilon _0A}{d}=\frac{8.85\times 10^{-12}\times 0.001256}{0.50\times 10^{-3}}=0.022\times 10^{-9}F$

(a) Total energy stored in the capacitor is equal to

$E=\frac{1}{2}CV^2$

$E=\frac{1}{2}\times 0.022\times 10^{-9}\times 200^2=0.044\times 10^{-5}J$

(b) Volume will be equal to $V=Ad$ , here A is area and d is distance between plates

$V=0.001256\times 0.02=2.512\times 10^{-5}m^3$

So energy density $=\frac{Energy}{volume}=\frac{0.044\times 10^{-5}}{2.512\times 10^{-5}}=0.0175J/m^3$

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3 years ago