Question

factor of tW 10. A loop of wire shown on the figure for problem 10 is placed in a uniform magnetic field directed into the page. The area of the loop decreases by a factor of three during a time interval of one second. 21) The magnetic flux through the loop a) increases by a factor b) increases by a of three c) decreases by a factor of three d) decreases by a f of nine factor of nine 22) The direction of the current induced in the loop a) is clockwise b) the current is zero c) is counterclockwise d) not enough info to make the conc 11. An AC circuit consisting of a resistor and an inductor connected in series is shown on the figure for problem 11. The rms current is 3 A. The resistance of the resistor is 3 92 and the inductance of the inductor is 0.01 H. The impedance of the circuit is 5 Ω. 23) What is the frequency of the alternating current? a) 127 Hz 24) What is the rms voltage? a) 10 V 25) What is the average power dissipated in the circuit? a) 48 W b) 31 Hz c) 64 Hz d) 21 Hz b) 30 V c) 20 V d) 15 V b) 27 W c) 108 W d) 12 W

Answer 1

10.

(21)

$\phi \propto A$

As the area of the loop decreases by a factor of 3, the magnetic flux also decreases by a factor of 3.

(22)

It is counterclockwise.

11.

(23)

$Z=\sqrt {(2\pi f L)^2+R^2}$

$f=\sqrt {\frac {Z^2-R^2}{4\pi^2L^2}}$

52 -32 4m3 . 0.012

f 64 Hz

(24)

$V_{rms}=I_{rms}Z=(3\times 5)\: V=15\: V$

(25)