Physics · 2025
JEE Main · 29 January 2025, Shift 2 · Q49
The magnetic field inside a 200 turns solenoid of radius 10 cm is 2.9 × 10^-4 Tesla. If the solenoid carries a current of 0.29 A, then the length of…
The magnetic field inside a $\displaystyle 200$ turns solenoid of radius $\displaystyle 10$ cm is $\displaystyle 2.9 \times 10^{-4} \mathrm{Tesla}$. If the solenoid carries a current of $\displaystyle 0.29$ A, then the length of the solenoid is $\displaystyle \_\_\_\_$ $\displaystyle \pi \mathrm{cm}$.
Official answer
From NTA’s final answer key for this paper.
8
More from Magnetic Field and Forces
- An infinitely long straight wire carrying current I is bent in a planer shape as shown in the diagram. The radius of the circular part is r. The…2026
- A proton is moving undeflected in a region of crossed electric and magnetic fields at a constant speed of 2 × 10^5 ms^-1. When the electric field is…2025
- An infinite wire has a circular bend of radius a, and carrying a current I as shown in figure. The magnitude of magnetic field at the origin O of the…2025
- A long straight wire of a circular cross-section with radius ' a ' carries a steady current I. The current I is uniformly distributed across this…2025
- Two identical circular loops P and Q each of radius r are lying in parallel planes such that they have common axis. The current through P and Q are I…2026
- A tightly wound long solenoid carries a current of 1.5 A. An electron is executing uniform circular motion inside the solenoid with a time period of…2025
- A current carrying solenoid is placed vertically and a particle of mass m with charge Q is released from rest. The particle moves along the axis of…2026
- In a moving coil galvanometer, two moving coils M_1 and M_2 have the following particulars: R_1=5 Ω, N_1=15, A_1=3.6 × 10^-3 m^2, B_1=0.25 T; R_2=7…2025
JEE Main 2025 Physics question, with the answer from NTA’s final answer key. Where our answers come from.