RRB Technician Grade 1 Model Paper 3

Concept:Pressure is defined as the force acting per unit area.Its SI unit is the pascal, which is $\mathrm{N\,m^{-2}}$.So, the dimensional formula of pressure is derived from $\mathrm{Force/Area}$.Explanation:Start with the basic relation:$$P = \frac{F}{A}$$Force is mass times acceleration:$$F = m \times a$$The dimensional formula of acceleration is:$$a = [L\,T^{-2}]$$So, the dimensional formula of force is:$$[F] = [M] \times [L\,T^{-2}] = [M\,L\,T^{-2}]$$The dimensional formula of area is:$$[A] = [L^{2}]$$Dividing force by area gives pressure:$$[P] = \frac{[M\,L\,T^{-2}]}{[L^{2}]} = [M\,L^{-1}\,T^{-2}]$$Therefore, the correct dimensional formula of pressure is $M\,L^{-1}\,T^{-2}$.Answer:The dimensional formula of pressure is $M\,L^{-1}\,T^{-2}$, which matches option B.