MCQ Questions for Class 11 Physics Chapter 2 Units and Measurements
Q.1. The density of a material in SI units is 128 kg m-3 . In certain units in which the unit of length is 25 cm and the unit of mass is 50 g, the numerical value of density of the material is
(a) 40
(b) 16
(c) 640
(d) 410
Answer
Answer: (a)Q.2. The quantity having the same unit in all system of unit is
(a) mass
(b) time
(c) length
(d) temperature
Answer
Answer: (b)Q.3. The damping force on an oscillator is directly proportional to the velocity. The unit of the constant of proportionality is
(a) kg-ms-1
(b) kg-ms-2
(c) kgs-1
(d) kg-s
Answer
Answer: (c)Q.4. If the value of work done is 1010 g-cm2 s-2 , then its value in SI units will be
(a) 10 kg-m2s-2
(b) 102 kg-m2s-2
(c) 104 kg-m2s-2
(d) 103 kg-m2s-2
Answer
Answer: (d)Q.5. The SI unit of thermal conductivity is
(a) J m-1K-1
(b) W-m K-1
(c) Wm-1K-1
(d) Jm K-1
Answer
Answer: (c)Q.6. Amongst the following options, which is a unit of time?
(a) Light year
(b) Parsec
(c) Year
(d) None of these
Answer
Answer: (c)Q.7. The ratio of the volume of the atom to the volume of the nucleus is of the order of
(a) 1015
(b) 1025
(c) 1020
(d) 1010
Answer
Answer: (a)Q.8. Which of the following measurement is most precise?
(a) 5.00 mm
(b) 5.00 cm
(c) 5.00 m
(d) 5.00 km
Answer
Answer: (a)Q.9. A student measured the length of a rod and wrote it as 3.50 cm. Which instrument did he use to measure it?
(a) Ameter scale
(b) A vernier calliper where the 10 divisions in vernier scale matches with 9 divisions in main scale and main scale has 10 divisions in 1 cm
(c) A screw gauge having 100 divisions in the circular scale and pitch as 1 mm
(d) A screw gauge having 50 divisions in the circular scale and pitch as 1 mm
Answer
Answer: (b)Q.10. The moon is observed from two diametrically opposite points A and B on earth. The angle θ subtended at the moon by the two directions of observation is 1°54′; given that the diameter of the earth to be about 1.276×107m. Compute the distance of the moon from the earth.
(a) 4.5x 109 m
(b) 3.83 x108 m
(c) 2.5 x 104 m
(d) 4 x107 m
Answer
Answer: (b)Q.11. A student measures the time period of 100 oscillations of a simple pendulum four times. The data set is 90s, 91s, 92s and 95s. If the minimum division in the measuring clock is 1s, then the reported mean time should be
(a) (92 ± 2)s
(b) (92 ± 5)s
(c) (92 ± 1.8)s
(d) (92 ± 3)s
Answer
Answer: (a)Q.12. The length, breadth and height of a rectangular block of wood were measured to be l = 12.13 ± 0.02 cm, b = 8.16 ± 0.01cm and h = 3.46 ± 0.01cm.
(a) 0.88%
(b) 0.58%
(c) 0.78%
(d) 0.68%
Answer
Answer: (b)Q.13. The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1×10-3 are
(a) 5, 1, 2 (b) 5, 1, 5
(c) 5, 5, 2 (d) 4, 4, 2
Answer
Answer: (a)Q.14. The numbers 5.355 and 5.345 on rounding off to 3 significant figures will give
(a) 5.35 and5.34 (b) 5.36 and5.35
(c) 5.35 and5.35 (d) 5.36 and5.34
Answer
Answer: (d)Q.15. Which two of the following five physical parameters have the same dimensions?
I. Energy density
II. Refractive index
III. Dielectric constant
IV. Young’s modulus
V. Magnetic field
(a) I and IV (b) III and V
(c) I and II (d) I and V