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Lad, PHYSICS ~ ares, eh Row wet, IMPORTANT FORMULAE, 1. ELECTROSTATICS GIST, S. No. FORMULAE SYMBOLS APPLICATION, 1. Q=+Ne Q= Charge, N= Number of | Quantization of charges, ~ Charge particle, 2. QQ, Q1, Q2 are point charges F=| To find force between tow, Fak Force point charges, 3. F=QE E = Electric field Relation between F and E, = 1 = di i, 4. E= 2 k me, °° distance peg alae toa, r €o= Absolute permittivity P ge, 5. Or te ‘a ef dscosg | 4S = small area To find electric flux, 6. Or =i @ = Electric Flux Gauss Theorem, 0, ze AV = potential difference To find the potential, Wes V,=Electric potentail atA _ | difference using Work, AV =V,-Ve=—q~ V.=Electric potentail atB | done from a point Ato a, q=charge point B, 8. ae 9 1 Electric potential due,, Yee = to a point charge, 41 Eo P g, r= distance :, 9. pcos@ p = dipole moment Electric potential due, V=k—, dipole, r, 10. —dV dV / dr=potential gradient Relation between electric, E= aF field and potential, 141: 7 ap U = Potential Energy Potential energy of a, FaWirk "12 W = Work done system of two point, Charges, I 3 r= li i Filed intensity due to, 12 _ 2.= linear charge density infinitely long. straight, 2M) R uniformly charged wire, 13. a) outside the shell: r= radius of Gaussian Filed intensity du to, , , , , , q, E=k—, 7), b) on the shell:, a = AR?, Pkt es, , E=a/€q, d) inside the shell : E=0, , , , surface (outside the shell), R=radius of shell, o =surface charge permittivity, , , , uniformly charged, spherical shell

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PHYSICS mares, adh frre, 14. o E = Electric field Field intensity due to thin, E= 2, €o= electric permittivity infinite plane sheet of, charge, 15. C = 4neor C=capacitance Capacity of isolated, r=radius of conductor spherical conductor, 16. € A A= area of plates Capacitance of a parallel, C=— d = distance between the | plate capacitor, d plates, 17. Grouped capacitors: C.= equivalent capacitance} To calculate equivalent, a) In series. in'series capacitance of a circuit, an 1 C,=equivalent capacitance, a= at S + oe in ’ parallel, ) In parallel:, C,=C,+C,+C,, 18. 1 Q? 3 U = Electrostatic energy Energy stored in a, U= 76° 5oV= 5 QV stored in capacitor capacitor, 19. 1 = E = electric field strength | Energy density of a, U= 2 & E* parallel plate capacitor, 20. CY, + CV; V = Common potential To find Common, . =—t+G potential due to sharing 4, a : charge, 21. ) C,Co(V> — V2)? E, - E, Loss fo energy Loss of energy due Sharing, y | i- = charges, 2(C, + C2), 22. K=1+% K = dielectric constant Relation between, x, = electric susceptibility dielectric constant &, electric susceptibility, 23. ce Co t =thickness of slab Capacitance of parallel, a-+) d=distance between the plate capacitor with, : plates conducting slab in, C,=capacitance between, 24. _ EA K=dielectric constant Capacitance of parallel, ~ d-ta— is plate capacitor with, x dielectric slab in between

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PHYSICS, , , , , , , , SZ, , Rabluban), ‘atta rere ere, , , , , , 25., , , , Values of Different quantities after Introducing dielectric slab between the plates, , of the charged capacitor :, , , , , , , , , , , , , , , , , , Description | When Battery connected When Battery disconnected, , Charge KQ Qo, , Potential Vo Vo/IK, , difference, , Electric E, E/K, , field, , Capacitance} KC, KCo, , Energy K times ee? [Energy | 1/K time 3,8? [Energy, is supplied By battery used for Polarization

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PHYSICS, , , , Unit-2 : CURRENT ELECTRICITY, , NZ, , ool wy, , ath ftarera rere, , , , , , , , , , , , , , , , , , , , , , , , , , , , S. No. FORMULAE SYMBOLS APPLICATION, _ Q@_ me l=current, Q=charged, t=time, | To find the current ina, 1. = t e=charge of electron current carrying wire., 2 = V=Potential difference, Relation between V, V = IR (Ohms law) R=resistance and |, 3. I= neAV, 7 V,=Drift Velocity Relation between, (n = number density of | A=area of cross section current and drift velocity, free electron), 4. pl ml Re Resistance , p = ay Relation between, Re ea = relaxation time, m= mass of] (i) R and A(ii) R and, electron relaxation time, 5. _ RA_™ e=charge of electron Relation for resistivity, Bs oT nee p =conductance, and relaxation time, 6. Get andostas C=conducatine,o =conductivity| To find C and o, R p RA, it IL j = current density, Relation between j with, =A = neVy o= conductivity V, and j with E, — =0E, 3) ) re vane = mobility of electron To find Lfrom V,, m, , , , , , , , , , , , , , , , , , , , P=po[1+a(T-To)] @ = temperature coefficient of Variation of P with, resistance temperature, = — Ranks _ :, 10. = ai(heTls) T, - T, = temperature difference |Formula for a, 11. |R,=R,+R +R + R, = equivalent resistance in Series combination, series combination, 12. |4/R, = 1/R, + /R, + WR, +.. = equivalent resistance in _| Parallel combination, iis combination, 13. P=VI=PR=W/R P = electrical power Relation for P with V, | and R, 14. | E=V+lr=1(R+r) E = emf of cell, Relation for E and V, 15. (1) VEE-Ir r = internal resistance (1) Current is drawn, (i) V=E +Ir V = Potential difference (ii) cell is being charged, 16. r=( ue 1)R r= internal resistance To find internal resistance, Q R = External resistance by potentiometer, 17. ne n=number of cells in series |Current drawn when n cells;, , , , , , , , i (Rtnr ), , , , R = External resistance, , , , are connected in series

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SE, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , PHYSICS mae, 18. me m = number of cells in parallel | Current drawn when n cells, (mR +r) are connected in parallel, 19. - mink m = number of rows ae ral oe une tb, (mR ynr) n = number of cells in each row, &Xternal resistance must be, equal to the total internal, resistance, 20. ZI = 0 (loop rule) Zlalgebraic sum of charge Kirchhoff s law, xAV = 0 (junction rule) | sy algebraic sum of potential, difference, 21: PLR P, Q, R, S are resistences in four} Balanced condition of, Qos arms of Wheatstone Bridge Wheatstone Bridge, 22. . =) R S = Unknown resistance Working condition for, t R = Known resistance Wheatstone Bridge, 23. V=EKL V= Potential drop a wire Principle of Potentiometer, L= Balancing length Cell., 24, Bolu E, and E,, emf of two cells Comparison of emf's of two, Fz |, and |, balancing length cell., q Unit-3 : MAGNETIC EFFECTS OF CURRENT AND MAGNETISM, ‘|SL.No} FORMULAE SYMBOLS APPLICATI, Tt y Biot - Savart Law | dB = magnetic field at a point at To find magnetic field at, distance r due to a current element] point due to current elem, 7 Ho = permeability of free space in fi, dB = #2, L#¢8in® | | = current through wire To le lies ie due to, an? = angle between current element} @ Straight conductor., Id| and position vector r., 2 tora? | B= magnetic field due to a circular |Magnetic field at centre, x = 0, B= ———7 | coilof N turns at distance X from its pe HoW!, 2(a?+ x? )2 | center. sie, a = Radius of coil, 3. Ho NI B = magnetic field magnetic field due to a, Be r= perpendicular straight conductor of infinite, distance from wire to length, point of observation., . | Ampere's circuital] -2 ae magnetic field due to a, - oe $B. dl =Line integral of arate B= UNI, = magnetic field in a closed path., $B. dl =yUol, FealVx B F = Force o Force acting on a charge, 5. F=q(V x B) V= velocity of charge particle particle in magnetic field., F=B qvsinO q = charge of the particle