Two uniformly distributed rings of charge, one of total charge Q1 ...

[abern]

Two uniformly distributed rings of charge, one of total charge Q1 and radius r1 and the other of total charge Q2 and radius r2, have the same center. The potential at the center is
 
  What will be an ideal response?

Question 2

An object 4.0 cm in height is placed 8.0 cm in front of a concave mirror with a focal length of 10.0 cm. What is the position of its image in relation to the mirror and what are its characteristics?
 
  A)
 
  40.0 cm on the other side of mirror, real, 6.0 times bigger
  B)
 
  10.0 cm on the other side of mirror, virtual, 10.0 times bigger
  C)
 
  18.0 cm on the same side of mirror, virtual, 2.25 times bigger
  D)
 
  10.0 cm on the same side of mirror, real, 6.0 times bigger
  E)
 
  40.0 cm on the other side of mirror, virtual, 5.0 times bigger

[ghepp]

Answer to Question 1

Q1/4 O r1 + Q2/4 O r2.

Answer to Question 2

E

[abern]

Thanks for the timely response, appreciate it

[abro1885]

Gracias!