Units and Measurements-Quiz-10

UNITS AND MEASUREMENTS QUIZ-10

Dear Readers,

JEE Advanced Physics Syllabus can be referred by the IIT aspirants to get a detailed list of all topics that are important in cracking the entrance examination. JEE Advanced syllabus for Physics has been designed in such a way that it offers very practical and application-based learning to further make it easier for students to understand every concept or topic by correlating it with day-to-day experiences. In comparison to the other two subjects, the syllabus of JEE Advanced for physics is developed in such a way so as to test the deep understanding and application of concepts.

Q1. The best method to reduce random error is

•  To change the instrument used for measurement
•  To take help of experienced observer
•  To repeat the experiment many times and to take the average results
•  None of the above

Solution

(c)
Random error is reduced by making large number of observations and taking mean of all the results

Q2. The dimensional formula for electric potential is

•  [M L² T^-3 A^-1]
•  [M L T^-3 A^-1]
•  [M L² T^-3 K^-1]
•  None of these

Solution

Q3. Which of the following is the most precise instrument for measuring length?

•  Metre rod of least count 0.1 cm
•  Vernier callipers of least count 0.01 cm
•  Screw gauge of least count 0.001 cm
•  Data is not sufficient to decide

Solution

(c)
Screw gauge has minimum least count of 0.001 cm; hence, it is the most precise instrument

Q4. Which of the following product of e, h, μ, G (where μ is the permeability) be taken so that the dimensions of the product are same as that of speed of light?

•  h e^-2 μ^-1 G⁰
•  h² e μ G⁰
•  h⁰ e² μ G^-1
•  h e^-2 μ⁰ G

Solution

Q5. A vernier callipers has 1 mm marks on the main scale. It has 20 equal divisions on the Vernier scale which match with 16 main scale divisions. For this Vernier callipers , the least count is

•  0.02 mm
•  0.05 mm
•  0.1 mm
•  0.2 mm

Solution

Q6. The length l, breadth b, and thickness t of a block of wood were measured with the help of a measuring scale. The result with permissible errors (in cm) are:
l = 15.12 ± 0.01, b = 10.15 ± 0.01, and t = 5.28 ± 0.01. The percentage error in volume up to proper significant figures is

•  0.28 %
•  0.35 %
•  0.48 %
•  0.64 %

Solution

Q7. If frequency F, velocity V, and density D are considered fundamental units, the dimensional formula for momentum will be

•  D V F²
•  D V² F^-1
•  D² V² F²
•  D V⁴ F^-3

Solution

Q8. The quantities A and B are related by the relation A/B=m, where m is the linear mass density and A is force, the dimensions of B will be

•  Same as that of pressure
•  Same as that of work
•  That of momentum
•  Same as that of latent heat

Solution

Q9. The dimensions of shear modulus of rigidity are

•  M¹ L¹ T^-2
•  M¹ L¹ T^-1
•  M L² T²
•  M L^-1 T^-2

Solution

Q10. Dimensional formula for torque is

•  L² M T^-2
•  L^-1 M T^-2
•  L² M T^-3
•  L M T^-2

Solution

(a)
Torque = force × distance =[M L² T^-2]