Field Long Straight Wire
Magnetic field at distance r from long straight wire carrying current I?
Select the correct option:
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
More magnetic effects and magnetism Practice Questions
Ampere's law integral form states ∮ B·dl equals?
Ampere's law integral form states ∮ B·dl equals?
Energy density u of magnetic field B in vacuum is?
Energy density u of magnetic field B in vacuum is?
Horizontal component of Earth's field Bh relates to total B and dip angle δ by?
Horizontal component of Earth's field Bh relates to total B and dip angle δ by?
Differential magnetic field dB due to current element Idl at position vector r (angle θ)?
Differential magnetic field dB due to current element Idl at position vector r (angle θ)?
Magnitude of magnetic force on charge q moving with velocity v perpendicular to uniform B?
Magnitude of magnetic force on charge q moving with velocity v perpendicular to uniform B?
Field at center of circular loop radius R carrying current I?
Field at center of circular loop radius R carrying current I?
Lorentz force vector expression?
Lorentz force vector expression?
Torque on N-turn rectangular loop area A carrying current I in uniform B (plane at angle θ) equals?
Torque on N-turn rectangular loop area A carrying current I in uniform B (plane at angle θ) equals?
Magnetic moment of single current loop (current I, area A)?
Magnetic moment of single current loop (current I, area A)?
A charge enters uniform B perpendicular to field. Path is?
A charge enters uniform B perpendicular to field. Path is?
Cyclotron angular frequency ω for charge q, mass m in magnetic field B?
Cyclotron angular frequency ω for charge q, mass m in magnetic field B?
Magnetic field inside long solenoid (turns per length n, current I) approximately?
Magnetic field inside long solenoid (turns per length n, current I) approximately?
About This Question
- Subject
- physics
- Chapter
- magnetic effects and magnetism
- Topic
- field long straight wire
- Difficulty
- Easy
- Year
- 2025
Solution
Correct Answer:
μ0 I /(2π r)
- Biot-Savart/Ampere's Law: For a long straight conductor, the magnetic field forms concentric circular loops around the wire.
- Ampere's Law Application: ∮B⋅dl=μ0I. For a circular path of radius r, B(2πr)=μ0I.
- Isolate B: B=2πrμ0I.
- Variables:
- μ0 is the permeability of free space (4π×10−7 T\cdotpm/A).
- I is the current and r is the radial distance from the wire.
- Direction: Determined by the Right-Hand Thumb Rule.
This easy difficulty physics question is from the chapter magnetic effects and magnetism, covering the topic of field long straight wire. It appeared in the 2025 exam.
Looking for more practice? Explore all physics questions or browse magnetic effects and magnetism questions on RankGuru.