Book Online Demo

Check Your IQ

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Q.

Four point charges Q_1,Q₂ , Q₃ and Q₄ are placed at the four corners A, B, C and D of a rectangle having sides 40 cm and 30 cm as shown in figure. Potential at the centre O is found to be 20 volt. If the charge Q₄ at corner D is removed, potential at O is found to be 2 volt. Then the value of Q₄ is

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

a

0.5 nC

b

3.75 nC

c

2.5 nC

d

6 nC

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail

Question Image

$\begin{array}{l} Length AC = BD = \sqrt{30^{2} + 40^{2}} cm = 50 cm . \\ Now, ∴ V = \frac{{KQ}_{1}}{AO} + \frac{{KQ}_{2}}{BO} + \frac{{KQ}_{3}}{CO} + \frac{{KQ}_{4}}{DO} \\ and V'= \frac{{KQ}_{1}}{AO} + \frac{{KQ}_{2}}{BO} + \frac{{KQ}_{3}}{CO} \\ Subtracting, V - V' = \frac{{KQ}_{4}}{DO} \Rightarrow 20 - 2 = 9 \times 10^{9} \times \frac{Q_{4}}{0 .25} \Rightarrow Q_{4} = 0 .5 n C \end{array}$

Watch 3-min video & get full concept clarity

hear from our champions

Related Blogs

Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

🔥 Start Your JEE/NEET Prep at Just ₹1999 / month - Limited Offer! Check Now!

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs

Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Books for IIT JEE

Best Books for NEET

Not sure what to do in the future? Don’t worry! We have a FREE career guidance session just for you!

Four point charges Q1, Q2 , Q3 and Q4 are placed at the four corners A, B, C and D of a rectangle having sides 40 cm and 30 cm as shown in figure. Potential at the centre O is found to be 20 volt. If the charge Q4 at corner D is removed, potential at O is found to be 2 volt. Then the value of Q4 is