Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Most Important Selected Qs for JEE AdvancedPhysicsElectromagnetic Induction

The circuit shows a resistance R =0.01 and inductance L =3 mH connected to a conducting rod PQ of length =2 ~m which can slide on a perfectly conducting circular arc of radius with its centre at P . Assume that friction & gravity are absent and a constant uniform magnetic field B=0.1 ~T exists as shown in the figure. At t =0 , the circuit is switched on and simultaneously an external torque is applied on the rod so t

Correct answer

4

Step-by-step solution

The half of the maximum current is equal to i ₁= B ^2 4 R at t = L R 2 The torque at this instant = B ^2 ^4 8 R =4 ~N - m

Practice Electromagnetic Induction on Quantrex Academy →

More from Electromagnetic Induction

List-I contains four conducting loops lying in the XY plane, as shown in the figures. The loops are rotating about Z axis passing through the point O with time period T in clockwis 2026A 30 cm long solenoid has 10 turns per cm and area of 5 cm ^2 . The current through the solenoid coil varies from 2 A to 4 A in 3.14 s. The e.m.f. induced in the coil is 10⁻⁵ V. Th 2026A square loop of side 2 cm is placed in a time varying magnetic field with magnitude as B = 0.4 (300t) Tesla. The normal to the plane of loop makes an angle of 60° with the field. 2026An inductor of inductance 10 mH having resistance of 100 , is connected to battery of E.M.F. 1.0 V through a switch as shown in the figure below. After switch is closed, the ratio 2026A metal rod of length L rotates about one end at origin with a uniform angular velocity . The magnetic field radially falls off as B(r) = B₀ e^ - r ; being a positive constant. The 2026A circular loop of radius 20 cm and resistance 2 is placed in a time varying magnetic field B = (2t^2 + 2t + 3) T . At t = 0 , for the plane of the loop being perpendicular to the 2026In the given circuit below inductance values of L₁ , L₂ and L₃ are same. The magnetic energy stored in the entire circuit is (U_t) and that stored in the L₂ inductor is (U_l) . U_t 2026A circular current loop of radius R is placed inside square loop of side length L(L >> R) such that they are co-planar and their centers coincide. The permeability of free space is 2026 Full Electromagnetic Induction list All Most Important Selected Qs for JEE Advanced PYQs