Q34.Consider a long straight wire of a circular cross-section (radius a) carrying a steady current I. The current is uniformly distributed across this cross-section. The distances from the centre of the wire's cross-section at which the magnetic field [inside the wire, outside the wire] is half of the maximum possible magnetic field, any where due to the wire, will be (1) [a/4, 3a/2] (2) [a/4, 2a] (3) [a/2, 2a] (4) [a/2, 3a]
What This Question Tests
The question tests the ability to calculate and compare magnetic field strengths both inside and outside a current-carrying cylindrical wire, requiring the application of Ampere's circuital law.
Concepts Tested
Formulas Used
B_in = (μ₀Ir) / (2πa²)
B_out = (μ₀I) / (2πr)
📚 NCERT Sections This Tests
4.8 — A Closely Wound Solenoid 80 Cm Long Has 5 Layers Of Windings Of 400
Physics Class 11 · Chapter 4
4.8 A closely wound solenoid 80 cm long has 5 layers of windings of 400 turns each. The diameter of the solenoid is 1.8 cm. If the current carried is 8.0 A, estimate the magnitude of B inside the solenoid near its centre.
4.6 — A 3.0 Cm Wire Carrying A Current Of 10 A Is Placed Inside A Solenoid
Physics Class 11 · Chapter 4
4.6 A 3.0 cm wire carrying a current of 10 A is placed inside a solenoid perpendicular to its axis. The magnetic field inside the solenoid is given to be 0.27 T. What is the magnetic force on the wire?
4.4 — A Horizontal Overhead Power Line Carries A Current Of 90 A In East To
Physics Class 11 · Chapter 4
4.4 A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?
📋 Question Details
- Chapter
- Magnetic Effects of Current
- Topic
- Magnetic field due to a long straight wire
- Year
- 2025
- Shift
- 29 Jan Shift 1
- Q Number
- Q34
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 4: Magnetic Effects of Current
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