ML{T^{ - 1}} represents the dimensional formula ofa. Powerb. Momentumc. Forced. Couple

To solve this, let's first analyze the dimensional formula of each quantity:
1. Power:
o Power is defined as work done per unit time.
o Work done = force × displacement.
o The dimension of force is [MLT−2][M L T^{-2}] and the dimension of displacement is [L][L].
o Therefore, the dimensional formula of work is [ML2T−2][M L^2 T^{-2}].
o Since power is work done per unit time, the dimension of power is: [ML2T−3][M L^2 T^{-3}]
2. Momentum:
o Momentum is defined as mass times velocity.
o The dimension of mass is [M][M], and the dimension of velocity is [LT−1][L T^{-1}].
o Therefore, the dimension of momentum is: [MLT−1][M L T^{-1}]
3. Force:
o Force is defined as mass times acceleration.
o The dimension of mass is [M][M], and the dimension of acceleration is [LT−2][L T^{-2}].
o Therefore, the dimension of force is: [MLT−2][M L T^{-2}]
4. Couple:
o A couple is a pair of forces with equal magnitude and opposite directions acting on a body, producing rotation.
o The dimension of a couple is the product of force and the distance between the two forces.
o The dimension of force is [MLT−2][M L T^{-2}], and the distance is [L][L].
o Therefore, the dimension of a couple is: [ML2T−2][M L^2 T^{-2}]
Conclusion:
The dimensional formula [MLT−1][M L T^{-1}] corresponds to momentum.
Thus, the correct answer is:
B) Momentum\boxed{\text{B) Momentum}}