Consider a dipole with dipole moment 4.8 × 10-30 cm. Let a point P lies 4.1 × 10-9 m away from centre of dipole. Match the values of potentials given in column-II with column-I and mark the correct choice from the given codes. Column I Column II i Point is along axis of dipole nearer to positive charge. p -1.8 × 10-3 V ii Point is 45° above the axis but nearer to positive charge. q 1.8 × 10-3 V iii Point is 45° above the axis but nearer to negative charge. r 2.6 × 10-3 V Codes:

Question

Consider a dipole with dipole moment 4.8 × 10-30 cm. Let a point P lies 4.1 × 10-9 m away from centre of dipole. Match the values of potentials given in column-II with column-I and mark the correct choice from the given codes. Column I Column II i Point is along axis of dipole nearer to positive charge. p -1.8 × 10-3 V ii Point is 45° above the axis but nearer to positive charge. q 1.8 × 10-3 V iii Point is 45° above the axis but nearer to negative charge. r 2.6 × 10-3 V Codes: (A) i-(p), ii-(r), iii-(q) (B) i-(q), ii-(p), iii-(r) (C) i-(r), ii-(q), iii-(p) (D) i-(q), ii-(r), iii-(p)

Tardigrade Admin · Accepted Answer

(i) V=(9 × 109 × 4.8 × 10-30 × cos 0°/(4.1 × 10-9)2) =2.6 × 10-3 V (ii) V=(k p cos θ/r2) =1.8 × 10-3 V (iii) V=(1/4 π ε0) ⋅ (p cos θ/r2) =(9 × 109 × 4.8 × 10-30 × cos 135°/(4.1 × 10-9)2) = -1.8 × 10-3 V

Column I		Column II
i	Point is along axis of dipole nearer to positive charge.	p	$- 1.8 \times 1 0^{- 3} V$
ii	Point is $4 5^{\circ}$ above the axis but nearer to positive charge.	q	$1.8 \times 1 0^{- 3} V$
iii	Point is $4 5^{\circ}$ above the axis but nearer to negative charge.	r	$2.6 \times 1 0^{- 3} V$

i-(p), ii-(r), iii-(q)

i-(q), ii-(p), iii-(r)

i-(r), ii-(q), iii-(p)

i-(q), ii-(r), iii-(p)

(i) V=(4.1×10−9)29×109×4.8×10−30×cos0∘​ =2.6×10−3V (ii) V=r2kpcosθ​ =1.8×10−3V (iii) V=4πε0​1​⋅r2pcosθ​ =(4.1×10−9)29×109×4.8×10−30×cos135∘​ =−1.8×10−3V