Answer:




Explanation:
r = Radius
k = Coulomb constant = 
Electric field is given by

The charge is 

The charge is 
The charge inside will have the polarity changed

Outside the charge will be

Answer:
5kgm
Explanation:
convert cm to m and g to kg
250/1000=0.25kg
5/1000=0.05m
then find the density
density=mass/volume
=0.25kg/0.05m
=5kgm
A concave mirror is opaque whereas a concave lens is transparent. ... Difference between concave mirror and concave lens is A concave mirror is opaque whereas a concave lens is transparent. A concave mirror causes reflection of light whereas a concave lens causes refraction of light.