Electrostatics Questions

A spherical conductor of radius $10\text{cm}$ has a charge of $3.2\times 10^{-7}\text{C}$ distributed uniformly. What is the magnitude of electric field at a point $15\text{cm}$ from the centre of the sphere?($\frac{1}{4\pi {ϵ}_0}=9\times 10^9{\text{N m}}^2{\text{/C}}^2$)

In a certain region of space with volume $0.2{\text{m}}^3$, the electric potential is found to be $5\text{V}$ throughout. The magnitude of electric field in this region is:

The capacitance of a parallel plate capacitor with air as medium is $6\mu \text{F}$. With the introduction of a dielectric medium, the capacitance becomes $30\mu \text{F}$. The permittivity of the medium is:(${ϵ}_0=8.85\times 10^{-12}{\text{C}}^2{\text{ N}}^{-1}{\text{ m}}^{-2}$)

A short electric dipole has a dipole moment of $16\times 10^{-9}\text{C m}$. The electric potential due to the dipole at a point at a distance of $0.6\text{m}$ from the centre of the dipole, situated on a line making an angle of $60^{\circ }$ with the dipole axis is:($\frac{1}{4\pi {ϵ}_0}=9\times 10^9{\text{N m}}^2{\text{/C}}^2$)