NEET-XI-Physics

exam-2 year:2016

with Solutions - page 4
 
  • Qstn #135
    An electric dipole is placed at an angle of 30° with
    an electric field intensity 2 X ``10^5`` N/C. It experiences
    a torque equal to 4 Nm. The charge on the dipole,
    if the dipole length is 2 cm, is :-
    (1) 5 mC
    (2) 7 µC
    (3) 8 mC
    (4) 2 mC
    digAnsr:   4
    Ans : (4)
    Sol.  = PE sin
     = q E sin 
    4 = q × 2 × 16-3 × 2 × 105 sin 30°
    &implies; q = 2 mC