[Music] current electricity foreign [Music] [Music] a flow of 10 to the power 7 electron per second in a contacting wire constitute a current of dash constitute a current of dash 10 to the power 7 into either value of 3 1.6 into 10 to the power minus 19 divided by 1 second chance of sum i am one not m so i equal to 3 1.6 into 10 to the power minus 12 ampere i equal to 1.6 into 10 to the power minus 12 ampere algorithm set okay equals simplification equality ten to the seven and ten to the power minus nine zero on it so ten to the power of minus two elements how many electrons do pass through a lamp in one minute if minus 3 into 10 to the power minus 3 so equal to 300 into 10 to the power minus 3 amp yep [Applause] i'm going to secondly load to match on that second clear so i equal to n e by t n therefore n equal to i t by e and the variable so n equal to either value of 3 on 300 into 10 to the power minus 3 into summa dhana divided by 1.6 into 10 to the power minus 19. so in the value of the sodium sorry one one two five zero into ten to the power sixteen one one two five zero into ten to the power sixteen another answer number one equal to one one two five zero into ten to the power foreign minus two t plus six in the over under charge in the expression find the expression of current current in the expression we have to find the expression of current okay yes square minus two t plus six so in theorem d by dt of two t square minus two t plus six minus two t plus six square minus 2 into d by dt of t plus d by dt of 6 okay yes minus two plus zero constant differential minus 2 so i equal to minus to sorry i equal to 40 minus 2 left right 4 t minus 2 1 m 40 minus 2 on it so 4 into 1 minus 2 in the m so i equal minus 2 l a equal to 0 not equate yeah so 40 minus 2 equal to 0 40 equal to 2 t equal to 2 by 4 what is the amount of charge flowing through the conductor when current becomes zero current [Applause] [Music] [Music] so 2 into 1 by 2 whole square 2 into 1 by 2 square minus 2 into 1 by 2 plus 6 clear so in the variable 2 into 1 by 4 minus 2 into 1 by 2 plus 6 on the variable so 2 canceling yeah if i cancel that 1 by 2 so 0.5 minus 1 plus six over zero point five minus one plus six seven equal to five point five column equal to five point five coulomb clear and shielding foreign the current passing through a contactor is directly proportional to the is directly proportional to the potential difference across the ends of the conductor current carrying contact passing through a contextual is directly proportional to the potential difference across the ends of the conductor conductor in the integral of potential difference directly proportionally so it depends upon [Music] [Music] depending on resistivity depends upon the nature of the material material in nature depending on okay from here resistivity simply defines number area of cross section one meter square is the resistance of the conductor when area of cross section is one meter square and length is one meter clear another easy idea defined cm independent resistivity is the resistance of the conductor when length is one meter and area of cross section oh resistivity of a material of a conductor is defined as the resistance of the conductor when length is one meter and area of cross section is one meter square so then the slope of a graph showing the variation of potential difference v on y-axis and current i on x-axis gives the contact conductors dash [Music] [Music] conducting wires of same material having same length which one have higher resistance justify with the relevant equation resistance foreign proportional to area of cross section r is inversely proportional to area of cross section the voltage [Applause] [Music] foreign equations 2 into 10 to the power minus 7 ohm [Music] [Music] foreign foreign so plus or minus 10 days into 10 to the power 5 plus or minus 10 percentage into 10 to the power 5 plus or minus 10 so 86 into 10 to the power of 4 plus or minus 5 percentage 86 into 10 to the power of 4 plus 4 minus 5 percentage so 47 into 10 to the power orange corresponding three plus or minus gold on it so five percent date okay so 47 into 10 to the power 3 plus 4 minus 5 percentage plus 4 minus 5 percent is [Music] [Music] foreign [Music] plus r two plus r three i u my um cancellation of clay i um i am cancellation so r equal to r one plus r two plus r three it's on a series connection la overall resistance on the is i 2 plus i 3 i equal to i 1 plus i 2 plus i 3 i am carrying i equal to n v by r i equal to v by r so v by r equal to v by r 1 plus v by r 2 plus b by r 3 b common i 2 4 telecom so v by r equal to b into 1 by r 1 plus 1 by r 2 plus 1 r1 plus 1 by r2 plus 1 by r3 in the rm foreign combination foreign arrange them in the increasing order of their equivalent resistance equivalent resistance in the increasing order arranges yeah equivalent [Music] [Music] equal to equal to 1 by r plus 1 by r plus 1 by r equal to 3 by r equal to 3 by r 1 um [Applause] so 1 by r equivalent equal to 1 by 2 r plus 1 by r lcm would come to our we come so 1 plus 2 equal to 3 by 2 r on the variable equal to 3 by 2 r foreign [Music] abcd resistance um [Music] so 1 by r equal to 2 by 5 so r equal [Music] foreign [Music] 75 plus 1 by 50 lcm and then lcm 150 i get it coming so in the clay 3 plus 2 plus 3 in the variable equal to 3 5 8 by 150 in [Applause] foreign two plus one equal to three by sixty in the room three by 20 1 by 10 equal to 0.1 ampere equal to 0.1 amp yeah okay ready ready okay equal to 1 by 10 equal to 0.1 ampere sweater an answer 0.1 ampere lcm so 1 by 31 by 16 dlc 1361 [Music] foreign foreign the amount of current entering to the junction will be equal to amount of current leaving from the junction the amount of current entering to [Applause] the amount of current entering to the junction will be equal to amount of current leaving from the junction at three on a current level i three i four i phi one so i three plus i four plus i five is i one plus i two equal to i three plus definitely [Music] [Music] [Applause] the algebraic sum of product of current and resistance will be equal to the emf in the circuit will be equal to the emf of the circuit board [Music] [Applause] foreign [Applause] v square [Music] foreign foreign 0.5 ampere [Music] foreign resistance will be equal to the yeah so i one p plus g i g g minus opposite direction opposite minus i 4 s minus i g g equal to 0 minus i g equal to 0. resistance foreign minus i two r equal to zero i three q minus i four s equal to zero i three q minus i four s equal to zero in the variable equation number four sorry q [Applause] [Music] foreign foreign foreign [Applause] equal to 1 by 2 plus 1 by 2 equal to 2 by 2 equal foreign foreign between foreign foreign [Music] put a four over m give it a four over m so one by r equal and equal to one by four plus one by four one by four plus one by four equal to two by four on the variable so two by four so our equivalent equal to [Music] [Applause] foreign [Music] [Applause] foreign minus l into r x by r equal to l r divided by 100 minus l into r y o i'm going to substitute a ampu so x by r equal to x by r equal to l r divided by 100 minus l rl divided by 100 minus l in the variable x equal to r l divided by 100 minus element okay so the final equation is foreign 12.50 39.5 divided by 60.5 into 12.5 and 7x in the value 8.16 ohm eight point one six ohm clear set element confusion [Applause] [Music] is directly proportional to the length potential drop is directly proportional to the length it is the principle of potentiometer either on a potentiometer in the principle right the potential drop is proportional to the length basically proportional to balance in length [Applause] [Music] [Music] so e divided by r plus r into r proportional to l is equation number one is equation number two at the staple equation one divided by two equation one divided by two so in the e by e divided by e r divided by r plus r r plus r equal to l naught divided by e denominator numerator e divided by 1 into r [Applause] m equal to l naught divided by ln over m so r plus r divided by r equal r plus r into l equal to r l naught of the value r plus r into l equal to r l naught eating mo to cross edu eating whatever so r plus r into l equal to r l naught to multiply so r l plus r small r equal to r into l naught minus l divided by ln r equal to r into l naught minus l divided by l either on a potentiometer in the final equation potentiometer so rl equal okay [Applause] so take care guys 7 30 bye