Visualising Potential

Q. Two concentric conducting spheres are of radii $r_1$ and $r_2$. The outer sphere is given a charge $q$. The charge $q^{\prime }$ on the inner sphere will be (inner sphere is grounded) :-

1. $q$
2. $-q$
3. $-q\frac{r_1}{r_2}$
4. Zero

Q. Two concentric conducting spheres are of radii $r_1$ and $r_2$. The outer sphere is given a charge $q$. The charge $q^{\prime }$ on the inner sphere will be (inner sphere is grounded) :-

1. $q$
2. $-q$
3. $-q\frac{r_1}{r_2}$
4. Zero