Ch 2 Formulas

Question 1

Potential

Answer 1

V=W/Q

Question 2

Potential energy

Answer 2

U=qv

Question 3

Potential due to point charge

Answer 3

V=1/4πεº.q/r

Question 4

Potential due to multiple charge

Answer 4

V=1/4πεº [nΣi=1.qi/ri]

Question 5

Potential due to dipole
i) At axial line
ii) Equitorial line
iii)At any orbitrary or.

Answer 5

V=1/4πεº.p/r³
V=0
V=kpcosθ/r²

Question 6

Potential energy of two point charge

Answer 6

U=1/4πεº.q¹.q²/r

Question 7

Potential energy of three point charges

Answer 7

U=1/4πεº[q¹.q²/r¹² + q¹.q³/r¹³ +q².q³/r²³]

Question 8

P.E of system of two points charges in external field

Answer 8

U=1/4πεº[q¹.q²/r¹²] + q¹Vr¹ + q²Vr²

Question 9

For conductor at a point inside it

Answer 9

a) q=0
b) E=0
E perpendicular surface of conductor

Question 10

Capacitance

Answer 10

C=Q/V

Question 11

Capacitance of // plate capacitor

Answer 11

Cº=εºA/d

Question 12

In series

Answer 12

1/Cs= 1/C¹ + 1/C²+….

Question 13

In parallel

Answer 13

CP= C¹+C²+….

Question 14

Capacitance with conducting slab bw the plate

if t=d

Answer 14

C= εºA/d-t

C=infinity

Question 15

Capacitance with dielectric slab bw the plate

If t=d

Answer 15

C=εºA/d-t+t/k

C=KCº

Question 16

Energy stored in capacitor

Answer 16

U=Q²/2C=1/2CV²=1/2QV

Question 17

Common potential

Answer 17

V=C1V1 + C2V2/ C1+C2

Question 18

When capacitor remain connected with battery

Answer 18

V=constant

Question 19

When capacitor disconnected from the battery

Answer 19

Q=Constant