CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Four positive charges (221)Q are arranged at the four corners of a square. Another charge q is placed at the centre of the square. Resulting field acting on each corner will be zero if q is

A
7Q4
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
4Q7
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
Q
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
(2+1)Q
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 7Q4

Given:
Q1=(221)Q
So, E1=kQ1a2
E2=kQ1(2a)2
E3=kq(a2)2
For net electric field to be zero,
E3+E1+E1+E2=0
E3 should balance electric field due to other charges, hence q should be negative in nature. Thus E3 acts towards charge q
|E3|=E21+E21+|E2| [From figure]
2kqq2=(kQ1a2)2+(kQ1a2)2+kQ12a2
2kqa2=2×kQ1a2+kQ12a2
2q=Q1[22+12]
q=Q1[22+14]
q=22+14×(221)Q
As q is negative in nature,
q=7Q4
Hence, option (a) is correct.

flag
Suggest Corrections
thumbs-up
35
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon