Electrostatics Question 688
Question: Among two discs A and B, first have radius 10 cn and charge $ {{10}^{-6}}\mu C $ and second have radius 30 cm and charge $ {{10}^{-5}}C. $ When they are touched, charge on both $ q _{A} $ and $ q _{B} $ respectively will, be
Options:
A) $ q _{A}=2.75\mu C,q _{B}=3.15\mu C $
B) $ q _{A}=1.09\mu C,q _{B}=5.5\mu C $
C) $ q _{A}=q _{B}=5.5\mu C $
D) None of these
Show Answer
Answer:
Correct Answer: C
Solution:
[c] The charge on disc A is $ {{10}^{-6}}\mu C. $
The charge on disc B is $ 10\times {{10}^{-6}}\mu C. $
The total this charge on both $ =11\mu C. $
When touched, this charge will be distributed equally i.e. $ 5.5\mu C $ on each disc.