1)A wheel having mass m has charges q and -q on diametrically opposite points .It remains in equilibrium on a rough inclined plane in  the presence of uniform  electric  field E   =

 

a)      Mg/ q

b)      Mg /2q

c)       Mg tanQ /2q

d)      None

Asked by thakurpratyush5 | 25th May, 2015, 07:14: PM

Expert Answer:

 
The forces acting on the dipole in the vertical direction are:
 
W = mg = weight of the wheel
 
F- = -qE = force on the negative charge in the downward direction
 
F+ = +qE = force on the positive charge in the upward direction
 
Hence, using the balancing equilibrium condition, we get
 
mg + F- = F+
 
mg - qE = qE
 
mg = 2qE
 
E = mg/2q

Answered by Romal Bhansali | 27th May, 2015, 03:36: PM