Question

I know I'm not supposed to ask 2 questions but if you could please help me on these questions it would help me so much and i will thank you endlessly, i have 2 questions left that i am stuck on but only one question left for chegg, I thank you so much in advance and I wish nothing but health and happiness for all you.

Problem 21.37 10 of 14 Constants Suppose 67 kW is to be transmitted over two 0.120 2 lines y Part A Estimate how much power is saved if the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120 V Assume the transformers are each 99% efficient Express your answer using two significant figures. Pal AΣΦ. ? Psaved - 35.7 kW Submit Previous Answers Request Answer X Incorrect; Try Again; 1 attempts remaining Next > Provide Feedback

Answer 1

arriving Solution a) Without transformers: Power at the town is 67kW. Since power is transmitted over two 0:12_2 Lines. .. In Single 0-12-22 line power is 33.5 KW Now cwment in each lines - I when V=120 V 1²x R 33.5 x103 - 120x I = I=279.16 A. power lost on the way in each line = R=0.122 .o I'R =1279.16)* 0'12 = 9351.63 W in power lost in both lines = 2x9351.63 W 18 70 3. 27 W = 18.70 kW 2 2

When V=1200 V I = 33. 5x108 -27.91 A. 1200 Power Lost in the way in each line = IZR (27.913 X0:12 = 93.47 W. oo power lost in the way in both lines = 2x93.47 -186.95 W = 0:187 kW Power lost via transformer in efficiency is 67kW X 8.01 = 670 W=0.67 kW és Total Pow or lost = 0.67 +0.187 = 0.857KW i. Power Saved= Psaved 18.7 -0.857) kW Psaved = 170843 kW Solution B) Let the distance of Image formed by diverging lens be a cm from converging lens towards left: Now using lens formula for converging lens: el f U → object distance (f focal length V fou con vorging lems = 17 cm o for converging lens = -8 cm f for conver converging 11.5cm S3 Image distance rens

- ㅗ 17 1 = ) - x 17 (-x) 1105 its ☆ towards left of the converging x= 35.54 cm lens. It means Image lens formed by diverging is (35.54 - 30)' = 5.54 cm towards left of it lens formula for diverging lens V = -5.54cm U = -25cm - (-25) - i 'O 1 f -5054 f 25 5.54 f - -70 l cm. .. focal length of the of the diverging lens =7.1cm