Page 1 : 71. The percentage errors in the measurement of mass, and speed are 2% and 3% respectively. How much, ‘will be the maximum error in the estimate of kinetic, energy obtained by measuring mass and speed?, , (2) 11% ——(b) 8% (0) 5% (a) 19%, , 72. Error in the measurement of radius of sphere is 2%., ‘The error in the measurement of volume is, (2) 1% (b) 59% (6) 3% (4) 6%, , 73. There are atomic clocks capable of measuring time, with an accuracy of 1 part in 101. If two such clocks, are operated with precision, then after running for, 5000 yr, these will record, , (a) a difference of nearly 25, (b) a difference of 1 day, {c) a difference of 10'!s, (4) a difference of 1 yr, , 74, If there is a positive error of 50% in the measurement, of speed of a body, then the error in the measurement,, of kinetic energy is,, , (a) 25% (b) 50% (4) 125%, , 75. The radius of the sphere is (4.3 + 0.1) cm. The, , percentage error in its volume is, , (c) 100 %, , , , (a) 2! 100 (Deena, 43 4, ieee fey yee, , wr, , 76. A public park, in the form of a square, has an area of, (100+ 0.2)m?. The side of park is, , {a) (10 + 0.01)m (b) (10 + 0.1)m, , (c) (10.04 0.1)m (a) (10.0 + 0.2)m, 71. The specific resistance p of a circular wire of radius r,, , Tw, , resistance R and length / is given by p = ey, , Given, r = 0: (24 + 0.02) em, R = (30 + 1) Qand, 1=(4,80 + 0.01) em. The percentage error inpis nearly, {a) 79% (b) 99%, (0) 139% (a) 20%, 78. The initial temperature of a liquid is (80.0 + 0.1)°C., After it has been cooled, its temperature is, (10.040.1)°C. The fall in temperature in degree, , centigrade is, (a) 70.0 (b) 70.0 + 0.3, (¢) 70.0 + 0.2 (a) 70.0 + 0.1, , 79, A physical quantity is represented by X=M‘LT™., ge errors in the measurements of M,L and, , B% and y% respectively, then total percentage, , {b) (aa + Bb + yc) %, (d) 0%, , Units and Measurements 23, , 80. The internal and external diameters of a hollow, , cylinder are measured with the help of a, vernier callipers. Their values are 4.23 + 0.01 em and, 3.87 + 0.01 cm respectively. The thickness of the wall of, the cylinder is, (a) 0.36 + 0.02 cm, {c) 0.36 + 0.01 cm, , (b) 0.18 + 0.02 em, (d) 0.18 + 0.01em, , 81. The density of the material of a cube is measured by, , measuring its mass and length of its side. If the, maximum errors in the measurement of mass and, the length are 3% and 2% respectively, the maximum, error in the measurement of density is, , (a)1% (b) 5%, , (co) 7% (d) 9%, , 82. When the planet Jupiter is at a distance of 824.7, , million km from the earth, its angular diameter is, measured to be 35.72’ ’ of arc. The diameter of Jupiter, , can be calculated as INCERT], , {a) 1329 x 10” km (b) 1429! x 10° km, , (c) 929 x 10° km (d) 1829 x 10° km, , 83. In an experiment, we measure quantities a, b and c., , ‘Then x is calculated from the formula, x = . The, , , , percentage errors in a, b,c are +1%, +3% and +2%, respectively. The percentage error in x can be, , (a) £19% (b) £49%, , {c) 7% (d) £13%, , 84. The time dependence of a physical quantity Pisgiven, , by P=Pe™ , where o is a constant and ¢ is time., , Then constant « is, (a) dimensionless, (c) dimensions of P, , (b) dimension of r*, (d) dimension of (7, , 85. The least count of a stop watch is 0.2 s. The time of, , 20 oscillations of a pendulum is measured to be 25 s., , The percentage error in the measurement of time, , will be, {a) 8% (b) 1.8%, , (c) 0.8 % (d) 0.19%, , 86. The pressure on a square plate is measured by, , measuring the force on the plate and the length of the, sides of the plate by using the formula p= y-If the, , maximum errors in the measurement of force and, length are 4% and 2% respectively, then the, maximum error in the measurement of pressure is, (a) 19% (b) 2% (c) 8% (a) 10%., 87. Given, potential difference V =(8 + 05) V and current, I =(2+0.2)A. The value of resistance R is, (a) 4 + 16.25% (b) 4 + 6.259, (c) 4 + 10% (d) 4 + 80%