Question

We have three identical metallic spheres A, B and C. $A$ is given a charge $Q$, and $B$ and $C$ are uncharged. The following processes of touching of two spheres are carried out in succession. Each process is carried out with sufficient time.

i A and B ii B and C

iii C and A iv A and B

v. B and C

The final charge on the sphere are :

• A. $\frac{11Q}{32},\frac{5Q}{16},\frac{11Q}{32}$
• B. $\frac{11Q}{32},\frac{11Q}{32},\frac{5Q}{16}$
• C. $\frac{8Q}{8},\frac{5Q}{16},\frac{5Q}{16}$
• D. $\frac{5Q}{16},\frac{11Q}{32},\frac{11Q}{32}$

Answer 1

The correct option is D $\frac{5Q}{16},\frac{11Q}{32},\frac{11Q}{32}$

Concept used:

$C=4\pi {\epsilon }_{0}r$ for each sphere

When 2 or more sphere are joined or touched, potential on them will be same. [$\frac{q_1}{C_1}=\frac{q_2}{C_2}$]

	QA	QB	QC
Initial	Q	0	0
AB	Q/2	Q/2	0
BC	Q/2	Q/4	Q/4
CA	3Q/8	Q/4	3Q/8
AB	Q/16	5Q/16	3Q/8
BC	5Q/16	11Q/32	11Q/32