✓ Board-verified
Physics · 2024 · 3 marks
CBSE 2024 · Region 3 · Set 1 · Q23
Two long straight parallel conductors carrying currents, exert a force on each other. Why? Derive an expression for the force per unit length between…
Two long straight parallel conductors carrying currents, exert a force on each other. Why ? Derive an expression for the force per unit length between two long straight parallel conductors carrying currents in opposite directions. Explain the nature of the force between these conductors.
Marking-scheme solution
Reason for exerting force on straight parallel conductors \(\displaystyle \frac{1}{2}\) Derivation for force per unit length $\displaystyle 2$ Explanation of nature of Force $\displaystyle 1$/$\displaystyle 2$ One conductor experiences a force due to magnetic field of the other conductor
Magnetic field produced by conductor 'a' at all points along the length of conductor 'b'
\[B_{a}=\frac{\mu_{0} I_{a}}{2 \pi d}
\] Force on conductor 'b' due to this magnetic field
\[\begin{aligned}
F_{b a} & =I_{b} L B_{a} \\
F_{b a} & =\frac{\mu_{0} I_{a} I_{b} L}{2 \pi d}
\end{aligned}
\]
\[f_{b a}=\frac{F_{b a}}{L}=\frac{\mu_{0} I_{a} I_{b}}{2 \pi d}
\] directed away from a
\[f_{a b}=\frac{F_{a b}}{L}=\frac{\mu_{0} I_{a} I_{b}}{2 \pi d}
\] directed away from b Repulsive, the forces acting on them are away from each other.
All Moving Charges and Magnetism questions2024 question paperNCERT solutions: Moving Charges and MagnetismPractice Moving Charges and Magnetism →
More from Moving Charges and Magnetism
- A 2.0 cm segment of wire, carrying 5.0 A current in positive y-direction lies along y -axis, as shown in the figure. The magnetic field at a point (3…2024
- Two thin long parallel wires A and B are separated by a distance r and carry current I each in the same direction. The force per unit length exerted…2023
- Derive an expression for the magnetic field B, due to a circular coil of N turns, each of radius r carrying current I, at a distance ' x ' from the…2026
- Assertion: A proton and an electron enter a uniform magnetic field B with the same momentum p such that p is perpendicular to B. They describe…2024
- Beams of electrons and protons move parallel to each other in the same direction. They2023
- (i) A particle of mass m and charge q is moving with a velocity v in a magnetic field B as shown in the figure. Show that it follows a helical path.…2024
- Figure shows a narrow beam of electrons entering with a velocity of 3 × 10^7 m / s, symmetrically through the space between two parallel horizontal…2026
- A particle of mass m and charge q moving with a uniform velocity v=v_0 x i+v_0 y j enters a region with a magnetic field B=B_0 j. After some time, an…2023
CBSE Class 12 Physics past-paper question from the 2024 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.