1 A person trying to lose weight by burning fat lifts a mass of 10kg up to a height of 1 m 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work done only when the weight is lifted up? Fat supplies 3.8 × 107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate (Take, g=9.8 ms-2) A) 2.45×10−3kg B) 6.45×10−3kg C) 9.89×10−3kg D) 12.89×10−3kg
2 The temperature dependence of resistance of Cu and undoped Si in the temperature range 300-400 K, is best described by A) Linear increase for Cu, linear increase for Si B) linear increase for Cu, exponential increase for Si C) linear increase for Cu, exponential decrease for Si D) Linear decrease for Cu, linear decrease for Si
3 Two identical wires A and B, each of length l, carry the same current I. Wire A is bent into a circle of radius R and wire B is bent to form a square of side a. If BA and BB are the values of the magnetic field at the centers of the circle and square respectively. then the ratio BABB is A) π28 B) π216√2 C) π216 D) π28√2
4 An observer looks at a distant tree of height 10 m with a telescope of magnifying power of 20. To the observer the tree appears A) 10 times taller B) 10 times nearer C) 20 times taller D) 20 times nearer
5 A screw gauge with a pitch of 0.5 mm and a circular scale with 50 divisions is used to measure the thickness of a thin sheet of Aluminium. Before starting the measurement. it is found that when the two jaws of the screw gauge are brought in contact, the 45th division coincides with the main scale line and that the zero of the main scale is barely visible. What is the thickness of the sheet, if the main scale reading is 0.5mm and the 25th division coincides with the main scale line? A) 0.75mm B) 0.80mm C) 0.70 mm D) 0.50mm
6 If the sum of first ten terms of the series (135)2+(225)2+(315)2+42+(445)2+...is165m,, then m is equal to A) 102 B) 101 C) 100 D) 99
7 If curve y=f(x) passes through the point (1,-1) and satisfies the differential equation y(1+xy)dx=xdy , then f(-1/2) is equal to A) −25 B) −45 C) 25 D) 45
8 The distance of the point (1,-5,9) from the the plane x-y+z=5 measured along the line x=y=z is A) 43 B) 10√3 C) 10√3 D) 203
9 If the line, x−32=y+2−1=z+43 lies in the plane, lx+my-z=9, then l2+m2 is equal to A) 26 B) 18 C) 5 D) 2
10 A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. lf e and mare charge and mass of an electron, respectively, then the value of h/λ, where λ is the wavelength associated with electron wave) is given by A) 2meV B) √meV C) √2meV D) meV
12 The distillation technique most suited to separating glycerol from spent lye rn the soap industry is A) fractional distillation B) steam distillation C) distillation under reduce pressure D) simple distilation
13 Decomposition of H2O2 follows a first-order reaction. In 50 min, the concentration of H2O2 - decreases from 0.5 to 0.25 in one such decomposition. When the concentration of H2O2 reaches 0.05 M, the rate of formation of O2 will be A) 6.93×10−4mol min−1 B) 2.66L/minat STP C) 1.34×10−2mol min−1 D) 6.93×10−2mol min−1
15 In the Hofmann-bromamide degradation reaction, the number of moles of NaOH and Br2 used Per mole of amine produce are A) 4 moles of NaOH and 2 moles of Br2 B) 2 moles of NaOH and 2 moles of Br2 C) 4 moles of NaOH and 1 mole of Br2 D) 1 mole of NaOH and 1 mole of Br2
