Electrostatics Question 350
Question: Two point charges $ Q $ and ? 3Q are placed at some distance apart. If the electric field at the location of $ Q $ is $ E $ then at the locality of $ -3Q $ , it is [BIT 1987]
Options:
A) $ -E $
B) $ E/3 $
C) $ -3E $
D) $ -E/3 $
Show Answer
Answer:
Correct Answer: B
Solution:
The field produced by charge ? 3Q at A, this is E as mentioned in the Example. $ \therefore $
$ E=\frac{3Q}{x^{2}} $ (along AB directed towards negative charge) Now field at location of ? 3Q i.e. field at B due to charge Q will be $ E’=\frac{Q}{x^{2}}=\frac{E}{3} $ (along AB directed away from positive charge)
