Solution - Career Point

10–10Column – Iφ(Magnetic flux)8 10 14 162 6t(s)× × × × × ×× × × × × ×× × × × × ×× × × × × ×× × × × × ×× × × × × ×Column – II(A) At 1s, induced current is (P) Clockwise(B) At 5s, induced current is (Q) Anticlockwise(C) At 9s, induced current is (R) Zero(D) At 15s, induced current is (S) 2A(T) None4. A conducting rod of length l is moved at constantvelocity v 0 on two parallel, conducting, smooth, fixedrails, which are placed in a uniform constant magneticfield B perpendicular to the plane of the rails asshown in figure. A resistance R is connected betweenthe two ends of the rail. Then which of the followingis/are correct ?R⊗ Bv 0⊗(A) The thermal power dissipated in the resistor isequal to the rate of work done by an externalperson pulling the rod(B) If applied external force is doubled, then a partof the external power increases the velocity ofthe rod(C) Lenz’s law is not satisfied if the rod isaccelerated by an external force(D) If resistance R is doubled, then power required tomaintain the constant velocity v 0 becomes half5. The x-z plane separates two media A & B ofrefractive indices µ 1 = 1.5 & µ 2 = 2. A ray of lighttravels from A to B. Its directions in the two media→are given by unit vectors µ 1 = a i + b j,µ 2 = c i + b j.Thena 4a 3(A) = (B) =c 3c 4(C)b 4b 3= (D) =d 3d 46. Two converging lenses of the same focal length f areseparated by distance 2f. The axis of the second lensis inclined at angle θ = 60ºwith respect to the axis ofthe first lens. A parallel paraxial beam of light isincident from left side of the lens. Then2f∧60º(A) Final image after all possible refraction willformed at optical centre of first lens(B) Final image after all possible refraction willformed at optical centre of second lens(C) Final image after all possible refraction willformed at distance f from second lens(D) Final image after all possible refraction willformed at distance f from first lens7. If C v for an ideal gas is given by C v = (3 + 2T)R,where T is absolute temperature of gas, then theequation of adiabatic process for this gas is(A) VT 2 = constant(B) VT 3 e -2T = C(C) VT 2 e 2T = constant(D) VT 3 e 2T = constant8. The pressure of one mole of ideal gas variesaccording to the law P = P 0 – αV 2 where P 0 & α arepositive constant constants. The highest temperaturethat gas may attain -(A)(C)2P0⎛ P0⎞⎜ ⎟3R ⎝ 3α⎠P0⎛ P0⎞⎜ ⎟R ⎝ 3α⎠1/ 21/ 2(B)(D)3P0⎛ P0⎞⎜ ⎟2R ⎝ 3α⎠P0 ⎛ P 0 ⎞⎜ ⎟R ⎝ α ⎠∧1/ 21/ 2→∧∧XtraEdge for IIT-JEE 15 APRIL 2010