Download NEET-UG 2013 Answer Key (Code - X) - Bansal Classes

Q.174 Ratio of longest wave lengths correspondingto Lyman and Balmer series in hydrogenspectrum is :Ans. 43(1) 239(3) 317(2) 295(4) 27Q.175 Infinite number of bodies, each of mass 2kgare situated on x-axis at distances1m, 2m, 4m,8m, ..........., respectively, from the origin. Theresulting gravitational potential due to thissystem at the origin will be :(1)8 G (2)3(3) –4G (4) –GAns. 34 G3Q.176 When a proton is released from rest in a room,it starts with an initial acceleration a 0towardswest. When it is projected towards north witha speed v 0is moves with an initial acceleration3a 0toward west. The electric and magneticfields in the room are :(1)(2)ma 0ema 0ewest,east,2maev003maev00downupQ.177 For a normal eye, the cornea of eye providesa converging power of 40 D and the leastconverging power of the eye lens behind thecornea is 20D. Using this information, thedistance between the retina and the corneaeyelens can be estimated to be :(1) 2.5 cm (2) 1.67 cm(3) 1.5 cm (4) 5 cmAns. 2Q.178 A parallel beam of fast moving electrons isincidentnormallyonanarrowslit.Afluorescentscreen is placed at a large distance from theslit. If the speed of the electrons is increased,which of the following statements is correct ?(1) Theangular width of the central maximumof the diffraction pattern will increase.(2) Theangular width of the central maximumwill decrease(3) Theangular width of the central maximumwill be unaffected.(4) Diffraction pattern is not observed on thescreen in the case of electronsAns. 2Q.179 Two pith balls carrying equal charges aresuspended from a common point bystrings onequallength,theequilibriumseparationbetweenthem is r. Now the strings are rigidly clampedat half the height. The equilibrium separationbetween the balls now becomes :Ans. 1(3)(4)ma 0ema 0eeast,west,3maev002maev00downup r (1) 3 2 2r (2) 3 y/2 2r (3) 3 Ans. 1(4)1 22