Consider three quantities x = E/B, y = and . Here, ℓ is the length of a wire, C is a capacitance and R is a resistance. All other symbols have standard meanings.


(A)Dimension for electric field E is: F/q = [MLT-3A-1]
Force due to magnetic field is given as: F=qvB.
Where q is the charge, v is the velocity of charge and B is the magnetic field.
Hence

The dimensions of charge, q is [AT]


The dimension of the velocity, V is [LT-1]


Putting the value in the above formula, we get


Dimensions of B =


Dimensions of B = [MT-2A-1]
Thus,



(B)

We know that
Where


μ0 is permeability of free space,


ϵ0 is the permittivity of free space and


c is the speed of light.
Thus, y = c, c is the speed and unit of speed is m/s
Dimensions of y = [LT-1]
(C)


Reactance,
Where


C is the capacitance


R is the resistance


l is the length of the wire.


In a CR circuit the product CR is the time constant and unit is seconds.
Thus, Dimensions of z = l/CR = m/s= [LT-1]
Hence x, y and z have same dimensions.
Thus, options (A),(B) and (C) are the correct options.

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