If electric field intensity at a certain distance from a dipole on its axis is E1 and at the same distance but on the perpendicular bisector of the dipole is E2, then __________
A. E1=E2
B. E1=2 E2
C. E1=4 E2
D. E1=3 E2
Answer:B
If electric field intensity at a certain distance from a dipole on its axis is E1 and at the same distance but on the perpendicular bisector of the dipole is E2, then __________
A. E1=E2 B. E1=2 E2 C. E1=4 E2 D. E1=3 E2
Explanation: If the dipole moment of a dipole is p, then electric field intensity at a distance r from the dipole on its axis will be \(\frac {2p}{r^3}\). But electric field intensity at a distance r from the dipole on its perpendicular bisector is \(\frac {p}{r^3}\). Both the formulas are derived by assuming r >> length of the dipole. Thus E1=\(\frac {2p}{r^3}\) and E2=\(\frac {p}{r^3}\) and hence E1=2 E2.