The equations and dimensional analysis are as follows:
The torque (\(\tau\)) is given by: \[ \tau = \mathbf{r} \times \mathbf{F} \implies [\tau] = [ML^2T^{-2}] \]
The magnetic field (\(\mathbf{B}\)) is derived as: \[ \mathbf{F} = [q \mathbf{v} \times \mathbf{B}] \implies [\mathbf{B}] = \frac{[\mathbf{F}]}{[q][\mathbf{v}]} = \frac{MLT^{-2}}{ATL^{-1}} = [MA^{-1}T^{-2}] \]
The magnetic moment (\(\mathbf{M}\)) has the dimensions: \[ [\mathbf{M}] = [\mathbf{I} \times \mathbf{A}] = [AL^2] \]
Using Biot-Savart's Law: \[ B = \frac{\mu_0 I dl \sin \theta}{r^2} \]
The permeability of free space (\(\mu\)) is derived as: \[ \mu = \frac{B r^2}{I dl} \implies \mu = \frac{MT^{-2}A^{-1} \times L^2}{AL} = [MLT^{-2}A^{-2}] \]
Thus, the correct matching is:
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: