Solution - Career Point

RP⊗BO ω 0Q19. A uniform solid cube is floating in a liquid as shown inthe figure, with part x inside the liquid. Some changes inparameters are mentioned in Column I. Assuming noother changes, match the following -x16. Magnitude of current as a function of time(A)(C)Bω l2RBω l8RWhere α =20 −αte20 −αte3B2 l 28RM(B)(D)Bω l16RBω l8R20 −2αte20 −2αte17. Total charge flow through resistance till rod PQ stoprotating .ω(A) 0 M ω(B) 0 M ω(C) 0 M ω(D) 0 M8B 3B 6B 9B18. Heat generated in the circuit by t = ∞(A)(C)Ml 2 ω2 024Ml 2 ω2 03(B)(D)Ml 2 ω2 08Ml 2 ω2 032SECTION – IVMatrix – Match TypeThis section contains 2 questions. Each questioncontains statements given in two columns, which haveto be matched. The statements in Column I are labeledA, B, C and D, while the statements in Column II arelabeled p, q, r, s and t. any given statement in Column Ican have correct matching with ONE OR MOREstatements (s) in column II. The appropriate bubbledcorresponding to the answers to these questions have tobe darkened as illustrated in the following example :If the correct matches are A – p, s and t; B – q and r;C – p and q; and D – s and t; then the correctdarkening of bubbles will look like the following.p q r s tABCDppqqrrrssttColumn IColumn II(A) If density of the liquid (p) Increasedecreases, x will(B) If height of the cube is (q) Decreasesincreased keeping base areaand density same, x will(C) If the whole system is (r) Remain sameaccelerated upward, thenx will(D) If the cube is replaced (s) May increaseby another cube of same or decreasesize but lesser density, x will(t) none20. A block of mass m = 1 kg is at rest with respect to arough wedge as shown in figure.mµθThe wedge starts moving up from rest with anacceleration of a = 2m/s 2 and the block remains at reswith respect to wedge then in 4 sec. of motion of wedgework done on block (assume angle of inclination ofwedge is θ = 30º and g = 10 m/s 2 ) –Column I(A) By gravity(B) By normal reaction(C) By friction(D) By all the forcesaColumn II(p) 144 J (in magnitude)(q) 32 J(r) 160 J(s) 48 J(t) noneXtraEdge for IIT-JEE 61APRIL 2010