A proton moving with a speed u in the x-y plane along the positive x axis enters at y=0 a region of uniform magnetic field B directed into the x-y plane as shown in Fig. After sometime, the proton leaves the region with a speed v at co-ordinate y. Then
v = u, y > 0
v = u, y < 0
v > u, y > 0
v > u, y < 0
F = q (u x B)} . Since force F is perpendicular to u, it does no work on the particle. Hence the speed of the proton remains unchanged, i.e. v = u [see Fig.]
From Fleming's L.H. rule, the force is directed upwards. Hence the proton, after completing a semicircle in the region of magnetic field emerges at positive y-coordinate.
So the correct choice is (a).
Study 40% syllabus and score up to 100% marks in JEE
5 g of Na2SO4 was dissolved in x g of H2O. The change in freezing point was found to be 3.820C. If Na2SO4 is 81.5% ionised, the value of x (K
A capacitor is made of two square plates each of side 'a' making a very small angle
A solution of m-chloroaniline, m-chlorophenol and m-chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO3 to give fraction A. The leftover organic phase was extracted with d