Advertisements
Advertisements
प्रश्न
Using Ampere's circuital law, obtain an expression for the magnetic flux density 'B' at a point 'X' at a perpendicular distance 'r' from a long current-carrying conductor.
(Statement of the law is not required).
Advertisements
उत्तर
Let AB, a long straight wire is carrying current i. The magnetic flux density `bar(B)` is to be required at point X at a distance r.
Let us draw a circle of radius r with centre O as shown in above figure. The point X lies on the circumference of the circle.
According to Ampere's circuital law,
`oint bar(B). bar(dl)= μ_0i. "where " bar(dl)` = infinitesimally small portion XY in the circle.
For complete circle, `bar(dl)= 2pir`
∴ `bar(B). 2pir = μ_0i`
⇒ `bar (B) = (mu_0)/(2pi).i/r NA^(-1)m^(- 1)`
⇒ `bar (B) = (mu_0)/(4pi).(2i)/r`
∴ `bar (B) = 10^-7 .(2i)/r NA^(-1)m^(- 1)`
APPEARS IN
संबंधित प्रश्न
State Ampere’s circuital law.
Obtain an expression for magnetic induction along the axis of the toroid.
In Ampere's \[\oint \vec{B} \cdot d \vec{l} = \mu_0 i,\] the current outside the curve is not included on the right hand side. Does it mean that the magnetic field B calculated by using Ampere's law, gives the contribution of only the currents crossing the area bounded by the curve?
In order to have a current in a long wire, it should be connected to a battery or some such device. Can we obtain the magnetic due to a straight, long wire by using Ampere's law without mentioning this other part of the circuit?
A hollow tube is carrying an electric current along its length distributed uniformly over its surface. The magnetic field
(a) increases linearly from the axis to the surface
(b) is constant inside the tube
(c) is zero at the axis
(d) is zero just outside the tube.
What is magnetic permeability?
The wires which connect the battery of an automobile to its starting motor carry a current of 300 A (for a short time). What is the force per unit length between the wires if they are 70 cm long and 1.5 cm apart? Is the force attractive or repulsive?
Briefly explain various ways to increase the strength of the magnetic field produced by a given solenoid.
Using Ampere’s circuital law, obtain an expression for magnetic flux density ‘B’ at a point near an infinitely long and straight conductor, carrying a current I.
