Question

PHYSathe PM 1 Phy143 T3 Elec-Man, Material Properties, Fluids F16 - Schermerhorn Mainly from homework 6, 7 and 8 1) if a current is flowing in a wire at point A out of this test paper, draw the magnetic field vector at point B to the right and point C below А, В 2) Find the current in amps to produce a magnetic field 3 of 02.67 Tesla at a position r = 2.25 m away from a long wire carrying the currentl. Hint: The equation given in Chapter 18 is B I 3) You lift a 100 lb sack of salt from the ground to the bed of a truck 3.50 ft above the ground. What is the total work done? 1) A charge of 100 Coulombs is moved from the electrical ground level to charge a 3.50 volt battery (positive level above the ground). What is the total work done? 5) What is the average) power of the battery charger if the battery in the above problem was charged in one hour. Give the answer in milliwatts W = 350 GO 60 6) Two electrons with charge q = 1.602 10 coulombs are separated by r * 0.1 cm. Find the electrostatic force between them where FE-k 99 9 = -1.602 10-19 q' = q r = 0.001 k = 9 109 7) What magnitude is the electrical field vector E at one of the electrons E = -6 9 [include the units in your answer] 8) What is the electrical potential V (sometimes called EMF [electro motive force]) in volts at one of the electrons and the associated energy in joules? (show the equation you use as well as the value] 9) Find the resistance of a one mile transmission line of two No. 24 copper wires which have a resistance rate of 0.0262 Ohm/ft. Assume 5280 feet in a mile 10) How much power is lost in the transmission line in problem 9) if it powers a 100 watt light operating at 120 volts rms. (assume current is in phase with the voltage) [HINT: First find the current in the light bulb that the power line needs to supply

Answer 1

1) Recall Amperes law The direction of magnelic field will be along tangent to the citacle drawn around conductor by sight hand ruleo 2) Given B = 2.67 jet AS BE MOI = Mo. ZAY IP 2.67x10x2.25 re 2.250 2.67X1D V 21 2.25 2x S, I = 30-0375 A Ans Recall W = mgh = 100x 0.454) x9,8 x(3.5X-3048) = 474.6 Jane 4) q= 100c WE qv = 100x3.5 = 350 Joul Ans. V=3-5V 5) p = ~= 350 = 97.2 mW Ans ans (0.1x102)2 6) Recame Fa relitz - 9x18x{160221549)"2.399% 1ā??os 5) Ezke - + gxidx t-boz 210 2.--1-418X106 NK me B) V- ke? - - Rel. -9x109x1.60281019 -1.4418x1öbv vel.646 xlox 1.602 x1019 – 2.30x15 25 jone 163 ans