Solution - Career Point

MOCK TEST – BIT-SATTime : 3 Hours Total Marks : 450Instructions :• This question paper contains 150 questions in Physics (40) Chemistry (40), Mathematics (45), LogicalReasoning (10) & English (15). There is Negative Marking• Each question has four option & out of them, ONLY ONE is the correct answer. There is – ve marking.• +3 Marks for each correct & – 1 Mark for the incorrect answer.PHYSICS1. If the amplitude of a damped oscillator becomes halfin 2 minutes, the amplitude of oscillation w.r.t. initialone after 6 minutes is1 1 11(A) (B) (C) (D) 27 8 18 642. An infinite number of spring having force constantsas k, 2k, 4k, 8k ..... ∞ and respectively are connectedin series; then equivalent spring constant is(A) k (B) 2k (C) k/2 (D) ∞3. A point particle of mass 0.1 kg is executing SHM ofamplitude 0.1 m when the particle passes through themean position. Its kinetic energy is 8 × 10 –3 J. Theequation of motion of this particle when the initialphase of oscillation is 45º can be given by⎛ π ⎞⎛ π ⎞(A) 0.1 cos ⎜4 t + ⎟ (B) 0.1 sin ⎜4t + ⎟⎝ 4 ⎠ ⎝ 4 ⎠⎛ π ⎞⎛ π ⎞(C) 0.4 sin ⎜ t + ⎟ (D) 0.2 sin ⎜ + 2t ⎟⎝ 4 ⎠ ⎝ 2 ⎠4. A mass m is moving with constant velocity along aline parallel to x-axis away from the origin. It angularmomentum with respect to origin.(A) is zero(B) remains constant(C) goes on increasing (D) goes on decreasing5. A vessel containing oil (density = 0.8g/cm 3 ) overmercury (density = 13.6 g/cm 3 ) has a homogeneoussphere floating with half of its volume immersed inmercury and other half in oil. The density of materialof sphere in g/cm 3 is(A) 3.3 (B) 6.4 (C) 7.2 (D) 2.86. Two trains move towards each other with the samespeed, speed of sound is 340 ms –1 . If the pitch of thetone of the whistle of one is heard on the otherchanges by 9/8 times then the speed of each train isV V(A) 2 ms –1 (B) 2000 ms –1(C) 20 ms –1 (D) 200 ms –17. A sound level I differ by 4 dB from another sound ofintensity 10 nW cm –2 . The absolute value of intensityof sound level I in Wm –2 is(A) 2.5 × 10 –4 (B) 5.2 × 10 –4(C) 2.5 × 10 –2 (D) 5.2 × 10 –28. An ideal gas is taken through the cycle A → B → C→ A as shown. If the net heat supplied to the gas inthe cycle 5J, the work done by the gas in the processC → A2V(m 3 )1CP(N/m 2 ) 10(A) – 5 J (B) – 15 J (C) – 10 J (D) –20 J9. There are n electrons of charge e on a drop of oil ofdensity ρ. It is in equilibrium in an electric field E.Then radius of drop is1/ 21/ 2⎛ 2neE ⎞⎛ neE ⎞(A)⎜4 g⎟ (B)⎝ πρ⎜⎠g⎟⎝ ρ ⎠⎛ 3neE ⎞(C)⎜4 g⎟⎝ πρ ⎠1/ 3⎛ 2neE ⎞(D)⎜g⎟⎝ πρ ⎠BA1/ 310. Two identical cells of emf 1.5 V and internalresistance 1 Ω are in series. A third cell of similarparameters is connected in parallel to theXtraEdge for IIT-JEE 76APRIL 2010