JEE Exam  >  JEE Questions  >  A Long straight wire ( radius =3.0mm) carries... Start Learning for Free
A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T?
Most Upvoted Answer
A Long straight wire ( radius =3.0mm) carries a constant current distr...
Given:
- Radius of the wire (r) = 3.0 mm = 0.003 m
- Current density (J) = 100 A/m²
- Distance from the axis of the wire (d) = 4.0 mm = 0.004 m

To Find:
The magnitude of the magnetic field at a distance of 4.0 mm from the axis of the wire.

Formula:
The magnetic field (B) due to a long straight wire at a distance (d) from the wire can be calculated using Ampere's Law:

B = μ₀ * J * (2πr)

Where:
- B is the magnetic field
- μ₀ is the permeability of free space (4π × 10⁻⁷ T·m/A)
- J is the current density
- r is the radius of the wire
- d is the distance from the wire

Calculation:
Substituting the given values in the formula:

B = (4π × 10⁻⁷ T·m/A) * (100 A/m²) * (2π * 0.003 m)

Simplifying:

B = (4π × 10⁻⁷ T·m/A) * (100 A/m²) * (6π × 10⁻³ m)

B = 24π² × 10⁻⁷ × 10⁻³ T

B = 24π² × 10⁻¹⁰ T

Approximating the value of π as 3.14:

B ≈ 24 * (3.14)² × 10⁻¹⁰ T

B ≈ 24 * 9.8596 × 10⁻¹⁰ T

B ≈ 236.63 × 10⁻¹⁰ T

B ≈ 2.3663 × 10⁻⁸ T

Rounding off to the appropriate number of significant figures:

B ≈ 2.4 × 10⁻⁸ T

Therefore, the magnitude of the magnetic field at a distance of 4.0 mm from the axis of the wire is approximately 2.4 × 10⁻⁸ T, which is closest to option (4) 4π × 10⁻⁸ T.
Explore Courses for JEE exam

Similar JEE Doubts

A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T?
Question Description
A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T?.
Solutions for A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
Here you can find the meaning of A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? defined & explained in the simplest way possible. Besides giving the explanation of A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T?, a detailed solution for A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? has been provided alongside types of A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? theory, EduRev gives you an ample number of questions to practice A Long straight wire ( radius =3.0mm) carries a constant current distributed uniformly over a cross section perpendicular to the axis of the wire. if current density is 100A/m2. the magnitude of the magnetic field at 4.0 mm from the axis of the wire is - (1) 3π/2×10^-8 T (2) π/2 ×10^-8T (3) 9π/2 × 10^-8T (4) 4π × 10 ^ -8T? tests, examples and also practice JEE tests.
Explore Courses for JEE exam

Top Courses for JEE

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev