Two long current carrying conductors are placed parallel to each other at a distance of 8 cm between them. The magnitude of magnetic field produced at mid-point between the two conductors due to current flowing in them is 30 μT. The equal current flowing in the two conductors is:
- 30 A in the same direction
- 30 A in the opposite direction
- 60 A in the opposite direction
- 300 A in the opposite direction
The Correct Option is B
Solution and Explanation
The correct answer is (B) : 30 A in the opposite direction
If currents are equal in both wires and field at mid-point is not zero, then the current is in opposite direction to sum up the fields at the point.
As Bnet ≠ 0 that is the wires are carrying current in opposite direction.
\(\frac{μ_0l × 2}{2π (4×10^{-2})} = 30 × 10^{-6} T\)
\(⇒ I = \frac{30 × 10^{-6}}{10^{-6}} A = 30 A\)
in opposite direction.
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Concepts Used:
Moving Charges and Magnetism
Moving charges generate an electric field and the rate of flow of charge is known as current. This is the basic concept in Electrostatics. Another important concept related to moving electric charges is the magnetic effect of current. Magnetism is caused by the current.
Magnetism:
- The relationship between a Moving Charge and Magnetism is that Magnetism is produced by the movement of charges.
- And Magnetism is a property that is displayed by Magnets and produced by moving charges, which results in objects being attracted or pushed away.
Magnetic Field:
Region in space around a magnet where the Magnet has its Magnetic effect is called the Magnetic field of the Magnet. Let us suppose that there is a point charge q (moving with a velocity v and, located at r at a given time t) in presence of both the electric field E (r) and the magnetic field B (r). The force on an electric charge q due to both of them can be written as,
F = q [ E (r) + v × B (r)] ≡ EElectric +Fmagnetic
This force was based on the extensive experiments of Ampere and others. It is called the Lorentz force.