Question

7) An ac source having a maximum voltage output of 419 V is connected in series with a 45-12 resistor, a 0.71- H inductor, and a 35-uF capacitor. What is the maximum charge on the capacitor when the frequency of the source is adjusted so that the circuit is in resonance? 8) A 101-loop coil having an area of 1.23 hm2 and a very large resistance is in a 7.174-mT uniform magnetic field oriented so that the maximum flux goes through the coil. The coil is then rotated so that the flux through it goes to zero in 7.43 s. What is the magnitude of the average emf induced in the coil during the 7.43 s?

Answer 1

7)

Given, Maximum output voltage & = 419 v Resistance R 452 current in resonance is given by Maximum Io εο R Io = 419 45 Maximum voltage across the capacitor given by V = Tote (where x = I is the - Joxl capacitive reactance w V = I x X DXC At resonance COL=L w² - L VLC 0.7)x35x10-6 W = 200.6 rad/s 200 = 200-6 rad's

Lit of be the maximum charge across the capacitor ols 3 from ega and en do 1 x 1p UXC To from egu V. 419 x / 250-200 6 45 do = 4.64810² C

8)

N=101 A = 1.23 hm? = 1.23X104 m² B = 7.174 410-3 T Masingum flux through the coil is given sy =NBA =101x7.174x153x1.230104 wb = 891.22 x 10 & = 8.91 x 103 wb Final magnetic fluce &=0 time t = 7.435 Average emf & induced in the coil is given & = - (& Pro) sy t = -(0 - 891X103) 7.43 = 8.918103 7.43 & = 112x103 volt