Q.

Sometimes it is convenient to construct a system of units so that all quantities can be expressed in terms of only one physical quantity. In one such system, dimensions of different quantities are given in terms of a quantity X as follows:

[position]=[Xα],  [speed]=[Xβ],  [acceleration]=[Xp],  [linear momentum]=[Xq],  [force]=[Xr]. Then     [2020]

1 α+p=2β  
2 p+q-r=β  
3 p-q+r=α  
4 p+q+r=β  

Ans.

(1, 2)

Given position, L=[Xα]

Speed, LT-1=[Xβ]

Acceleration, LT-2=[Xp]

Linear momentum, MLT-1=[Xq]

Force, MLT-2=[Xr]

Position÷Speed=time,   T=[Xα][Xβ]=Xα-β

Acceleration=SpeedTime=XβXα-β=Xp

Xα-β+p=Xβ   α+p=2β

Hence option (1) is correct.

Force=linear momentumtime

[Xr]=[Xq][Xα-β]r=q+β-αr=q+β-(2β-p)

r=q-β+pp+q-r=β

Hence option (2) is correct.