CH 2 JEE 1.The period of a body under is represented by T P a D b S c ; where P is pressure, D is density and S is surface tension. The value 1 3 1 1 , , (d) 1, 2 , 2 2 2 3 X 2.The dimensions of physical quantity X in the equation Force is given by (a) M 1 L4T 2 (b) M 2 L2T 1 density of a, b and c are (a) 3 1 , ,1 (b)-1, -2, 3 2 2 (c) M 2 L2T 2 (d) M 1L2T 1 3.Dimensions of CR are those of (c) (a)frequency (b)energy (c)time period (d)current 4.A force F is given by F at bt , where t is time. What are the dimensions of a and b 2 (a) MLT 3 and ML2T 4 (b) MLT 3 and MLT 4 (c) MLT 1 and MLT 0 5.The physical quantity which has dimensional formula as that of (a)force (b)power (c)pressure (d) MLT 4 and MLT 1 energy is mass length (d)acceleration 6.If L, C and R denote the inductance, capacitance and resistance respectively, the dimensional formula for C 2 LR is (a) ML2T 1 I 0 (c) M 1 L2T 6 I 2 (b) M 0 L0T 3 I 0 (d) M 0 L0T 2 I 0 7.The dimensional formula for young’s modulus is (a) ML1T 2 (b) M 0 LT 2 (c) MLT 2 (d) ML2T 2 8.If force ( F), length (L) and time (T) are assumed to be fundamental units, then the dimensional formula of the mass will be (a) FL1T 2 (b) FL1T 2 (c) FL1T 1 (d) FL2T 2 9.In a system of units if force (F), acceleration (A) and time (T) are taken as fundamental units then the dimensional formula of energy is (a) FA2T (b) FAT 2 (c) F 2 AT (d)FAT 10.The period of oscillation of a simple pendulum is given by T= 2 l where l is about 100 cm and is known to have 1mm g accuracy. The period is about 2s. The time of 100 oscillations is measured by a stop watch of least count 0.1 s. The percentage error in g is (a)0.1 % (b)1 % (c)0.2 % (d)0.8 % 11.The percentage errors in the measurement of mass and speed are 2% and 3% respectively. How much will be the maximum error in the estimation of the kinetic energy obtained by measuring mass and speed (a)11 % (b)8 % (c)5 % (d)1 % 12.A body travels uniformly a distance of 13.8 0.2 m in a time 4.0 0.3 s . The velocity of the body within error limits is (a) 3.45 0.2 ms 1 (b) 3.45 0.3 ms 1 (c) 3.45 0.4 ms 1 (d) 3.45 0.5 ms 1 V where V 100 5 volts and i 10 0.2 amperes. What is the total error in R i 5 (b)7% (c)5.2% (d) % 2 13.The resistance R (a)5% 14.The period of oscillation of a simple pendulum in the experiment is recorded as 2.63 s, 2.56 s, 2.42 s, 2.71 s and 2.80 s respectively. The average absolute error is (a)0.1 s (b)0.11 s (c)0.01 s (d)1.0 s 15.According to joule’s law of heating, heat produced H I 2 Rt , where I is current, R is resistance and t is time. If the errors in the measurement of I, R and t are 3%, 4% and 6% respectively then error in the measurement of H is (a) 17 % (b) 16 % (c) 19 % (d) 25 % 16.The percentage errors in the measurement of length and time period of a simple pendulum are 1 % and 2 % respectively. Then the maximum error in the measurement of acceleration due to gravity is (a)8 % (b)3 % (c)4 % (d)6 % (e)5 % 1 17. A physical quantity P is given by P A3 B 2 4 C D 3 2 . The quantity which brings in the maximum percentage error in P is (a)A (b)B (c)C (d)D 18. A sphere of radius ‘r’ moving in a viscous medium with velocity ‘v’. If the resistive force on it is given by F 6 rv , then 1 1 dimensional formula of coefficient of viscocity will be.......... (a) ML T 1 (b) MT 2 (c) MLT 3 (d) ML 19. One planet is observed from two diametrically opposite points A and B on the earth. The angle subtended at the planet by the two directions of observations is 1.8 . given the diameter of the earth to be about 1.276 107 m. What will be distance of the planet from the earth ? (a) 13.8 108 m (b) 3.84 106 km (c) 4.06 108 m (d) 4.06 106 km 20. Force F A cos Bx C sin Dt , where x in meter and t in time then find dimensional formula of 0 0 0 (a) M L T 0 0 1 (b) M L T 0 1 0 (c) M LT 0 1 1 (d) M LT D . B

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# measurement and system of units