Problem in electrostatics: E-field near 2 point charges

AI Thread Summary
The discussion revolves around a problem involving the electric field and potential energy near two point charges of unequal magnitudes. The user calculates the electric field at a large distance, concluding that options c and d are correct, while option a is incorrect. There is confusion regarding the calculation of angle beta, but it is noted that this angle is not necessary to disqualify option b. The problem originates from the 2016 NEST exam in India. The conversation highlights the complexities of electrostatics in relation to point charges.
ubergewehr273
Messages
139
Reaction score
5

Homework Statement


Refer the image.

Homework Equations


kq1q2/r^2 = F
Potential energy = kq1q1/r

The Attempt at a Solution


Obviously since both charges are unequal in magnitude option a is incorrect.
Calculating field at large distance r,
E = kq1/r^2 - kq2/r^2
= kq2/r^2
Also potential energy at q1 is lesser than near q2 for negative charge.
So options c,d are correct. However I don't understand how the angle beta can be calculated from the given information.
 

Attachments

  • Screenshot-2018-5-26 master_A dvi - NEST2016_A pdf.png
    Screenshot-2018-5-26 master_A dvi - NEST2016_A pdf.png
    35 KB · Views: 417
Physics news on Phys.org
ubergewehr273 said:
However I don't understand how the angle beta can be calculated from the given information.
No need to calculate the angle to disqualify answer b.
 
Doc Al said:
No need to calculate the angle to disqualify answer b.
I'm sorry but I don't quite understand. The answers given are b,c,d.
 
Hmm. What book is this from?
 
Doc Al said:
Hmm. What book is this from?
It's from an exam paper called NEST (National Entrance Screening Test) conducted in India. Its for the year 2016.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Electric field at the center of the equilateral triangle
Replies
10
Views
3K
Electrostatic force on a test charge by uniformly charged annular disc
Replies
1
Views
705
Force between point charges at the center of two spherical shells
Replies
4
Views
2K
What is the magnitude of the field at point R?
Replies
5
Views
2K
Can a dipole be modeled as a point charge?
Replies
10
Views
527
Why Is Work Positive When Done Against the Electric Field?
Replies
22
Views
3K
Coulomb's Law Grade 12 Question -- Net Electric Field affecting a Charge
Replies
18
Views
4K
Why is source force + electrostatic force = 0 inside battery?
Replies
10
Views
1K
Method of mirroring - metal plates
Replies
11
Views
2K
At what point is Electric Potential zero
Replies
2
Views
2K

Hot Threads

Recent Insights

Back
Top