The electric flux is \(ϕ=\alpha \sigma +\beta \lambda\) where \(\lambda\) and \(\sigma\) are linear and surface charge d…
The electric flux is \(ϕ=\alpha \sigma +\beta \lambda\) where \(\lambda\) and \(\sigma\) are linear and surface charge density, respectively. \(\left(\frac{\alpha }{\beta }\right)\) represents
[JEE Main 2025, 23 Jan (Shift 1)]
displacement
The electric flux \(\phi\) has dimensions of charge per unit area, i.e.,:
\([ϕ]=\left[\frac{Q}{\text{ Area }}\right]\)
a is associated with surface charge density s , which has the dimensions:
\([\sigma ]=\frac{Q}{\text{ Area }}\)
Thus, the dimensions of a will be:
\([\alpha ]=\left[\frac{ϕ}{\sigma }\right]=\frac{Q/\text{ Area }}{Q/\text{ Area }}=1\)
Next, for 1 , the linear charge density, we have:
\([\lambda ]=\frac{Q}{\text{ Length }}\)
Since b is associated with 1 , the dimensions of b are:
\([\beta ]=\left[\frac{ϕ}{\lambda }\right]=\frac{Q/\text{ Area }}{Q/\text{ Length }}=\frac{\text{ Length }}{\text{ Area }}\)
Now, considering the ratio \(\frac{\alpha }{\beta }\), we find:
\(\left[\frac{\alpha }{\beta }\right]=\frac{1}{\frac{\text{ Length }}{\text{ Area }}}=\text{ Length }\)
Thus, the ratio \(\frac{\alpha }{\beta }\) represents length.
Practice more JEE Physics PYQs
See every question on Electric Charges and Fields, or browse the full JEE question bank.
See all questions on Electric Charges and Fields →