Two point charges +10 q and -4 q are located at x = 0 and x = L… | MHT CET 2024 (10 May, Shift 1)

Q17MHT CET 2024 · 10 MAY · SHIFT 1Medium

Electric Field & Field Lines

Two point charges +10 q and -4 q are located at $x = 0$ and $x = L$ respectively. What is the location of a point on the $x$ -axis from the origin, which the net electric field due to these two point charges is zero?( $r =$ required distance $)$

Show answer and solution

Answer: (a)

The null point lies beyond the smaller charge $-4q$ at B, at distance $r$ to its right.
$\dfrac{10q}{(L+r)^2} = \dfrac{4q}{r^2} \Rightarrow \dfrac{r}{L+r} = \dfrac{\sqrt{2}}{\sqrt{5}}$
$r\sqrt{5} = \sqrt{2}L + \sqrt{2}r \Rightarrow r = \dfrac{\sqrt{2}\,L}{\sqrt{5} - \sqrt{2}}$ , right of B
So the answer is (a).

Report a mistake

More questions on Electric Field & Field Lines

If the net electric field at point P along Y axis is zero, then the ratio of |(q₂)/(q₃)|…JEE Main 2024 (8 Apr, Shift 2)
Electric field in a certain region is given by E = (A/x²i + B/y³j). The SI unit of A and…JEE Main 2023 (30 Jan, Shift 1)
Two equal positive point charges are separated by a distance 2a. The distance of a point…JEE Main 2023 (1 Feb, Shift 1)
A point charge of 10 μ C is placed at the origin. At what location on the X-axis should a…JEE Main 2023 (25 Jan, Shift 2)
A uniformly charged semicircular arc of radius ' r ' has linear charge density ' λ '. The…MHT CET 2023 (14 May, Shift 1)
Two point charges A and B of magnitude +8 × 10 - 6 C and - 8 × 10 - 6 C respectively are…JEE Main 2022 (28 Jun, Shift 2)
Two point charges Q each are placed at a distance d apart. A third point charge q is…JEE Main 2022 (29 Jun, Shift 2)
The three charges q/2, q and q/2 are placed at the corners A, B and C of a square of side…JEE Main 2022 (28 Jun, Shift 1)

Electric Field & Field Lines question from MHT CET 2024 (10 May, Shift 1)

More questions on Electric Field & Field Lines