Step 1: Use the relationship between µ0, ϵ0, and the speed of light.- Given $c = \frac{1}{\sqrt{\mu_0 \epsilon_0}}$, we know:
$\frac{1}{\mu_0 \epsilon_0} = c^2$.
Step 2: Analyze the dimensions.- Dimensional formula for c: [c] = $\frac{L}{T}$.- Hence, $[\frac{1}{\mu_0 \epsilon_0}]$ = $[c^2]$ = $\frac{L^2}{T^2}$.
Final Answer: The dimension is $\frac{L^2}{T^2}$
A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)): 

In the first configuration (1) as shown in the figure, four identical charges \( q_0 \) are kept at the corners A, B, C and D of square of side length \( a \). In the second configuration (2), the same charges are shifted to mid points C, E, H, and F of the square. If \( K = \frac{1}{4\pi \epsilon_0} \), the difference between the potential energies of configuration (2) and (1) is given by: