Q 1 :    

The density of a material in SI units 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                                [2019]         

  • 410

     

  • 640

     

  • 16

     

  • 40

     

(D) Density ρ=ML3

           n1u1=n2u2

   128[M1L1-3]=n2[M2L2-3]

     n2=128[M1M2][L2L1]3    =128×[100050]×[25100]3

          =128×20×164=40



Q 2 :    

If E and H represent the intensity of electric field and magnetising field respectively, then the unit of E/H will be                  [2021]

  • joule

     

  • ohm

     

  • newton

     

  • mho

     

(B) Unit of EH is volt/metreAmpere/meter=voltAmpere=ohm

 



Q 3 :    

Match List l with List II.                                                  [2021]

                        List I          List II
a) RH (Rydberg constant) (i) kg m-1 s-1
b) h (Planck's constant) (ii) kg m2 s-1
c) μB (Magnetic field energy density) (iii) m-1
d) η (Coefficient of viscosity) (iv) kg m-1 s-2

 

Choose the most appropriate answer from the options given below:

  • (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)

     

  • (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)

     

  • (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)

     

  • (a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)

     

(A) SI unit of Rydberg constant = m-1

      SI unit of Plank's constant = kg m2s-1

      SI unit of Magnetic field energy density = kg m-1s-2

      SI unit of Coefficient of viscosity = kg m-1s-1

 



Q 4 :    

Match List I with List II.                                                  [2022]

         List I          List II
A. Torque I. Nms-1
B. Stress II. J Kg-1
C. Latent Heat III. Nm
D. Power IV. Nm-2

 

Choose the correct answer from the options given below:

  • A-III, B-II, C-I, D-IV

     

  • A-III, B-IV, C-II, D-I

     

  • A-IV, B-I, C-III, D-II

     

  • A-II, B-III, C-I, D-IV

     

(B) Torque = F×rNm

      Stress = ForceArea=N/m2

      Latent heat = EnergyMass=JKg-1

      Power = WorkTime=Nms-1

 



Q 5 :    

Given below are two statements:                                                                                                                           [2023]

Statements I: Astronomical unit (Au). Parsec (Pc) and Light year (ly) are units for measuring astronomical distances.

 

Statements II: Au < Parsec (Pc) < ly

 

In the light of the above statements. choose the most appropriate answer from the options given below:

  • Both Statements I and Statements Il are correct.

     

  • Statements I is correct but Statements II is incorrect.

     

  • Both Statements I and Statements II are incorrect.

     

  • Statements I is incorrect but statements II is correct,

     

(B)    1 AU=1.496×1011m

         1 par sec=3.08×1016m

         1 light year=9.46×1015m

         So, Au<ly<Par sec

 



Q 6 :    

Consider a block and trolley system as shown in the figure.
If the coefficient of kinetic friction between the trolley and the surface is 0.04, the acceleration of the system in m-2 is:
(Consider that the string is massless and un-stretchable and the pulley is also massless and frictionless).                            [DEMO]

  • 3

     

  • 4

     

  • 2

     

  • 1.2

     

DEMO