How does tha force between the two point charges change if the dielectric constant of the medium in are kept, increas3s?

Example. 3one end of an aluminium wire, whose diameteris 2.5 mm is welded to one end of a copper wirewhose diameter is 2.0 mm. the composite wirecarries a steady current 6.25 a. the currentdensities in al and cu will be respectively(a) 127 a/cm2, 200 a/cm2(b) 126 a/cm2, 180 a/cm? (c) 125 a/cm2, 160 a/cm2(d) 125 a/cm, 180 a/cm2​

What are the uses of concave mirror?

How many percentage of losses in hydroelectric power generation?