Q 1 :

The equation of stationary wave is:                                                     [2024]

 

y=2asin(2πntλ)cos(2πxλ).

 

Which of the following is not correct?

  • The dimensions of x is [L]

     

  • The dimensions of nt is [L]

     

  • The dimensions of n is [LT-1]

     

  • The dimensions of n/l is [T]

     

(4)

       y=2asin(2πntλ)cos(2πxλ)

      (i) [x]=L

      (ii) [2πntλ]=1[nt]=1·[λ]=L

      (iii) [nt]=L[n]=LT-1

      (iv) [nλ]=LT-1L=T-1

 



Q 2 :

Applying the principle of homogeneity of dimensions, determine which one is correct, where T is time period, G is gravitational constant, M is mass, r is radius of orbit.                                                      [2024]

  • T2=4π2r3GM

     

  • T2=4π2r2GM

     

  • T2=4π2r3

     

  • T2=4π2rGM2

     

(1) 

     According to principle of homogeneity dimension of LHS should be equal to dimensions of RHS. [T2]=T2,

     Dimension of G is [M-1L3T-2]

      Now,

      (1) [4π2r3GM]=L3M-1L3T-2M1=T2

      (2) [4π2r2GM]=L2M-1L3T-2M1=L-1T2

      (3) [4π2r3]=L3

      (4) [4π2rGM2]=LM-1L3T-2M2=M-1L-2T2

 



Q 3 :

If G be the gravitational constant and u be the energy density then which of the following quantity have the dimensions as that of the uG.        [2024]

  • Force per unit mass

     

  • Gravitational potential

     

  • pressure gradient per unit mass

     

  • Energy per unit mass

     

(1) 

       [uG]=[(M1L-1T-2)(M-1L3T-2)]

       [uG]=[M0L2T-4]

       [uG]=[L1T-2]

 



Q 4 :

What is the dimensional formula of ab-1 in the equation (P+aV2)(V-b)=RT, where letters have their usual meaning.        [2024]

  • [M6L7T4]

     

  • [ML2T-2]

     

  • [M-1L5T3]

     

  • [M0L3T-2]

     

(2) 

      [V]=[b] It means the dimension of b=[L3]

      [P]=[aV2][a]=[PV2]=[ML-1T-2][L6]

      Dimension of a=[ML5T-2]

         ab-1=[ML5T-2][L3]=[ML2T-2]

 



Q 5 :

Match List-I with List-II:                                                        [2024]

                List I              List II
A Torque (I) [M1L2T-2A-2]
B Magnetic Field (II) [L2A1]
C Magnetic moment (III) [M1T-2A-1]
D Permeability of free space (IV) [M1L2T-2]

 

Choose the correct answer from the options given below:

  • A-III, B-l, C-II, D-IV

     

  • A-IV, B-II, C-III, D-I

     

  • A-IV, B-III, C-II, D-I

     

  • A-I, B-III, C-II, D-IV

     

(3) 

      [τ]=[r×F]=[ML2T-2]

      [B]=[MLT-2ATLT-1]=[MA-1T-2]

      [M]=[I×A]=[AL2]

      B=μ04π Idl sinθr2[μ]=[Br2Idl]

      [μ]=[MT-2 A-1×L2AL]=[MLT-2 A-2]



Q 6 :

Given below are two statements:                                                                [2024]

 

Statements (I): Dimensions of specific heat is [L2T-2K-1]

 

Statements (Il): Dimensions of gas constant is [ML2T-1K-1]

 

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

  • Both statement (I) and statement (lI) are correct

     

  • Statement (I) is incorrect but statement (II) is correct

     

  • Statement (I) is correct but statement (II) is incorrect

     

  • Both statement (I) and statement (II) are incorrect

     

(3) 

       Specific heat, s=QmT=[ML2T-2][MK]=[L2T-2K-1]

       Statement-(I) is correct

       PV=nRTR=PVnT

       [R]=[ML-1T-2][L3][mol][K]

       [R]=[ML2T-2mol-1K-1]

      Statement-II is incorrect



Q 7 :

If 0 is the permittivity of free space and E is the electric field, then 0E2 has the dimensions                                [2024]

  • [M0L-2TA]

     

  • [ML-1T-2]

     

  • [M-1L-3T4A2]

     

  • [ML2T-2]

     

(2) 

       Energy per unit volume = 120E2

       120E2[ML-1T-2]=0E2



Q 8 :

The dimensional formula of latent heat is                                 [2024]

  • [M0LT-2]

     

  • [MLT-2]

     

  • [M0L2T-2]

     

  • [ML2T-2]

     

(3)  

      Q=mL.[L]=[Q][m]

       [L]=[ML2T-2M]=[M0L2T-2]



Q 9 :

The de-Broglie wavelength associated with a particle of mass m and energy E is h/2mE. The dimensional formula for Planck's constant is                [2024]

  • [ML-1T-2]

     

  • [ML2T-1]

     

  • [MLT-2]

     

  • [M2L2T-2]

     

(2) 

        Given λ=h2mE

        h=λ2mE or h=λp

         So dimensional formula of Planck's constant

         [h]=[length][Mass×velocity]

          =[L1][M1L1T-1]=[ML2T-1]



Q 10 :

Given below are two statements:                                                              [2024]

 

Statement (I): Planck's constant and angular momentum have same dimensions.

 

Statement (II): Linear momentum and moment of force have same dimensions.

 

In the light of the above statements, choose the correct answer from the options given below:

 

  • Statement I is true but Statement II is false

     

  • Both Statement I and Statement II are false

     

  • Both Statement I and Statement II are true

     

  • Statement I is false but Statement II is true

     

(1)  

       [h]=ML2T-1

       [L]=ML2T-1

       [P]=MLT-1

       [τ]=ML2T-2

       (Here h is Planck's constant, L is angular momentum, P is linear momentum and τ is moment of force)



Q 11 :

The equation of state of a real gas is given by (P+aV2)(V-b)=RT, where P,V and T are pressure, volume and temperature respectively and R is the universal gas constant. The dimensions of ab2 is similar to that of:                                     [2024]

  • PV

     

  • P

     

  • RT

     

  • R

     

(2)  

       [P]=[aV2][a]=[PV2]

       And [V]=[b]

       [a][b2]=[PV2][V2]=[P]



Q 12 :

Match List-I with List-II                                                           [2024]

  List-I   List-II
A. Coefficient of viscosity I. [ML2T-2]
B. Surface tension II. [ML2T-1]
C. Angular momentum III. [ML-1T-1]
D. Rotational kinetic energy IV. [ML0T-2]
  • A-II, B-I, C-IV, D-III

     

  • A-I, B-II, C-III, D-IV

     

  • A-III, B-IV, C-II, D-I

     

  • A-IV, B-III, C-II, D-I

     

(3)     

          (A) Coefficient of viscosity

           F=6πηrv

           [M1L1T-2]=[η][M0L1T0][M0L1T-1]

            [η]=[M1L1T-2][M0L1T0][M0L1T-1]=[M1L-1T-1](III)

           (B) Surface Tension

           (T)=Fl=[M1L1T-2][M0L1T0]=[M1L0T-2](IV)

           (C) Angular momentum

           mvr=[M1L0T0][M0L1T-1][M0L1T0]

           =[M1L2T-1](II)

           (D) Rotational Kinetic Energy

            [M1L2T-2](I)

 



Q 13 :

If mass is written as m=kcPG-1/2h1/2 then the value of P will be (Constants have their usual meaning with k a dimensionless constant)         [2024]

  • 1/2

     

  • 1/3

     

  • 2

     

  • - 1/3

     

(1)  

        m=KCPG-1/2h1/2                                ...(1)

       G=Fr2m1·m2=MLT-2·L2M2=[M-1L3T-2]

        Now using (1)

        [M]=[LT-1]P [M-1L3T-2]-1/2 [ML2T-1]1/2

        Compare the dimension of T from L.H.S and R.H.S then

        -P+12=0P=12



Q 14 :

A force is represented by F=ax2+bt1/2 where x = distance and t = time. The dimensions of b2/a are                        [2024]

  • [ML2T-3]

     

  • [ML3T-3]

     

  • [ML-1T-1]

     

  • [MLT-2]

     

(2)  

       F=ax2+bt1/2

       [a]=[F][x2]=[M1L-1T-2]

      [b]=[F][t1/2]=[M1L1T-5/2]

      [b2a]=[M2L2T-5][M1L-1T-2]=[M1L3T-3]



Q 15 :

Consider two physical quantities A and B related to each other as E=B-x2At where E,x and t have dimensions of energy, length and time respectively. The dimension of A B is                         [2024]

  • L-2M1T0

     

  • L2M-1T1

     

  • L-2M-1T1

     

  • L0M-1T1

     

(2) 

       [B]=L2

       A=x2tE=L2TML2T-2=1MT-1

       [A]=M-1T

       [AB]=[L2M-1T1]

       

 



Q 16 :

The dimensional formula of angular impulse is                                       [2024]

  • [ML-2T-1]

     

  • [ML2T-2]

     

  • [MLT-1]

     

  • [ML2T-1]

     

(4) 

        Angular impulse = change in angular momentum.

       [Angular impulse] = [Angular momentum] = [mvr]

       = [ML2T-1]

 



Q 17 :

If B is magnetic field and μ0 is permeability of free space, then the dimensions of (B/μ0) is          [2025]

  • MT2A1

     

  • L1A

     

  • LT2A1

     

  • ML2T2A1

     

(2)

Magnetic field at the axis of a long solenoid, B=μ0ni

[Bμ0]=[ni]=L1A



Q 18 :

Which one of the following is the correct dimensional formula for the capacitance in F? M, L, T and C stand for unit of mass, length, time and charge,          [2025]

  • [F]=[C2M2L2T2]

     

  • [F]=[CM2L2T2]

     

  • [F]=[CM1L2T2]

     

  • [F]=[C2M1L2T2]

     

(4)

C=qV=qV·qq=q2Work done

  [F]=[C2][ML2T2]=[C2M1L2T2]



Q 19 :

The position of a particle moving on x-axis is given by x(t) = A sin t + cos2t + Ct2+ D, where t is time. The dimension of ABCD is          [2025]

  • L

     

  • L3T2

     

  • L2T2

     

  • L2

     

(3)

Dimension [x(t)] = [L]

[A] = [L]

[B] = [L]

[C] = [LT2]

[D] = [L]

[ABCD]=[L×L×LT2L]=[L2T2]



Q 20 :

The electric flux is ϕ=ασ+βλ, where λ and σ are linear and surface charge density, respectively, (αβ) represents          [2025]

  • charge

     

  • electric field

     

  • displacement

     

  • area

     

(3)

ϕ=ασ+βλ

[ϕ]=[ασ]=[βλ]

[α]=[ϕ][σ]  [β]=[ϕ][λ]

[α][β]=[Q/L][Q/Area]=[AreaLength]

[αβ]=L



Q 21 :

Match List I with List II

  List I   List II
(A) Permeability of free space I. [ML2T2]
(B) Magnetic field II. [MT2A1]
(C) Magnetic moment III. [MLT2A2]
(D) Torsional constant IV. [L2A]

 

Choose the correct answer from the options given below :          [2025]

  • (A)-(I), (B)-(IV), (C)-(II), (D)-(III)

     

  • (A)-(II), (B)-(I), (C)-(III), (D)-(IV)

     

  • (A)-(IV), (B)-(III), (C)-(I), (D)-(II)

     

  • (A)-(III), (B)-(II), (C)-(IV), (D)-(I)

     

(4)

B=μ0I2πr

 [μ0]=[B·rI]=[MT2A1×LA]=[MLT2A2]

magnetic field F = qvB

B=[MLT2ATL/T]=[MT2A1]

[M]=[L2A]

τ=Cθ  C=[τθ]=[ML2T2]



Q 22 :

The energy E and momentum p of a moving body of mass m are related by some equation. Given that c represents the speed of light, identify the correct equation.          [2025]

  • E2=pc2+m2c4

     

  • E2=pc2+m2c2

     

  • E2=p2c2+m2c2

     

  • E2=p2c2+m2c4

     

(4)

We need to check the dimensions only.

[E]=M1L2T2

[Pc]=M1L1T1·L1T1=M1L2T2

[mc2]=M1L2T2

So, E2=p2c2+m2c4 (dimensionally)



Q 23 :

Match List I with List II

  List I   List II
A Angular Impulse (I) [M0L2T2]
B Latent Heat (II) [ML2T3A1]
C Electrical Resistivity (III) [ML2T1]
D Electromotive Force (IV) [ML3T3A2]

 

Choose the correct answer from the options given below :          [2025]

  • (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

     

  • (A)-(I), (B)-(III), (C)-(IV), (D)-(II)

     

  • (A)-(III), (B)-(I), (C)-(II), (D)-(IV)

     

  • (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

     

(1)

Angular impulse = [ML2T1]

Latent Heat = [M0L2T2]

Electrical Resistivity = [ML3T3A2]

Electromotive Force = [ML2T3A1]



Q 24 :

The pair of physical quantities not having same dimensions is          [2025]

  • Torque and energy

     

  • Surface tension and impulse

     

  • Angular momentum and Planck's constant

     

  • Pressure and Young's modulus

     

(2)

[Angular momentum] = ML2T1

[Planck's Constant] = ML2T1

[Torque] = ML2T2

[Energy] = ML2T2

[Surface tension] = MT2

[Impulse] = MLT1

[Pressure] = ML1T2

[Young's modulus] = ML1T2



Q 25 :

The expression given below shows the variation of velocity (v) with time (t), v=At2+BtC+t. The dimension of ABC is :          [2025]

  • [M0L2T3]

     

  • [M0L1T3]

     

  • [M0L1T2]

     

  • [M0L2T2]

     

(1)

v=At2+BtC+t

[v]=[A]t2=[BtC+t]

[A] = LT3

[C] = T

[B] = LT1

[ABC] = L2T3



Q 26 :

Match List I with List II.

  List I   List II
(A) Young's Modulus (I) ML1T1
(B) Torque (II) ML1T2
(C) Coefficient of Viscosity (III) M1L3T2
(D) Gravitational Constant (IV) ML2T2

 

Choose the correct answer from the options given below :          [2025]

  • (A)-(I), (B)-(III), (C)-(II), (D)-(IV)

     

  • (A)-(II), (B)-(I), (C)-(IV), (D)-(III)

     

  • (A)-(IV), (B)-(II), (C)-(III), (D)-(I)

     

  • (A)-(II), (B)-(IV), (C)-(I), (D)-(III)

     

(4)

(A) [Y]=FA(ll)  MLT2L2=ML1T2

(B) Torque (τ)=r×F=L×MLT2=ML2T2

(C) Coefficient of viscosity  F=ηAdVdt

          [η]=MLT2L2×T=ML1T1

(D) Gravitational constant (G)

          F=GM1M2r2

          [G]=F·r2m1m2=MLT2×L2M2=M1L3T2



Q 27 :

The equation for real gas is given by (P+aV2)(Vb)=RT, where P, V, T and R are the pressure, volume, temperature and gas constant, respectively. The dimension of ab2 is equivalent to that of :          [2025]

  • Planck's constant

     

  • Compressibility

     

  • Strain

     

  • Energy density

     

(4)

Given, [P+aV2](Vb)=RT

[P]=[aV2]  [a]=[P][V2]

[a]=[P][V2]=[ML1T2][L6]=ML5T2

[b]=[V]=L3

[ab2]=[ML5T2L6]=[ML1T2]

Dimension of energy density.



Q 28 :

Match List I with List II

  List I   List II
(A) Coefficient of viscosity (I) [ML0T3]
(B) Intensity of wave (II) [ML2T2]
(C) Pressure gradient (III) [M1LT2]
(D) Compressibility (IV) [ML1T1]

 

Choose the correct answer from the options given below :          [2025]

  • (A)-(I), (B)-(IV), (C)-(III), (D)-(II)

     

  • (A)-(IV), (B)-(I), (C)-(II), (D)-(III)

     

  • (A)-(IV), (B)-(II), (C)-(I), (D)-(III)

     

  • (A)-(II), (B)-(III), (C)-(IV), (D)-(I)

     

(2)

ηFlAv[ML1T1] IV
IPA[MT3] I
dPdx[ML2T2] II
K1B[M1LT2] III

 



Q 29 :

Given a charge q, current I and permeability of vacuum μ0. Which of the following quantity has the dimension of momentum?          [2025]

  • qI/μ0

     

  • qμ0I

     

  • q2μ0I

     

  • qμ0/I

     

(2)

Momentum = mv

r=mvqB

[mv][qBr]  [mv][qμ0I2πrr]

 [mv][qμ0I]



Q 30 :

If μ0 and ε0 are the permeability and permittivity of free space, respectively. then the dimension of (1μ0ε0) is :          [2025]

  • L/T2

     

  • L2/T2

     

  • T2/L

     

  • T2/L2

     

(2)

C=1μ0ε0

μ0ε01C2[L2T2]

 [1μ0ε0]=L2T2