October 2022

Q. Which of the following pairs has the same dimensions? Specific Heat and Latent Heat Impulse and Momentum Surface Tension and Force Moment of Inertia and Torque Answer: Impulse and Momentum

Q. The equation of state of some gases can be expressed as Vander wal equation i.e. (P +a/v2)(V – b) = RT Where P is the pressure, V is the volume, T is the absolute temperature and a, b, R are constants. The dimensions of ‘a’ are: [M1L1T-1] [M1L-5T1] [M2L5T-1] [M1L5T-2] Answer: [M1L5T-2]

Q. Which of the following pairs of physical quantities does not have same dimensional formula? Work and torque. Angular momentum and Planck’s constant Tension and surface tension Impulse and linear momentum Answer: Tension and surface tension

Q. The mean length of an object is 5 cm. Which of the following measurements is most accurate? 4.9 cm 4.805 cm 5.25 cm 5.4 cm Answer: 4.9 cm

Q. The number of significant figures in 600 m is 1 2 3 4 Answer: 3

Q. Young’s modulus of steel is 1.9 × 1011 N/m2. When expressed in CGS units of dynes/cm2, it will be equal to (1N = 105 dyne, 1m2 = 104 cm2) 1.9 × 1010 1.9 × 1011 1.9 × 1012 1.9 × 1013 Answer: 1.9 × 1012

Q. You measure two quantities as A = 1.0 m ± 0.2 m, B = 2.0 m ± 0.2 m. We should report correct value for √AB as: 1.4 m ± 0.4 m 1.41m ± 0.15 m 1.4m ± 0.3 m 1.4m ± 0.2 m Answer: 1.4m ± 0.2 m

Q. The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give 2.75 and 2.74 2.74 and 2.73 2.75 and 2.73 2.74 and 2.74 Answer: 2.74 and 2.74

Q. The sum of the numbers 436.32, 227.2 and 0.301 in appropriate significant figures is 663.821 664 663.8 663.82 Answer: 664

Q. What is the unit for measuring the amplitude of a sound? Decibel Coulomb Hum Cycles Answer: Decibel