Question

3. A straight wire of length 1 and electric dipole moment p is
bent to form a semicircle. The new dipole moment would
be
(A)r/2
LBY 22
(C)/2 p
(D) 2p​

Answer 1

Initial dipole moment, p=q×l

When it is bent in the form of semi circle, l=pie RR=l/pie. Now the charges are present diametrically opp. Point of the semi circle. Dis. Between the charges=2R+2l/pie.new dipole moment, p=q×2r=q×(2l/pie)=2p/pie

Hope it helps!!!!