Irodov – Problems in General Physics

Fig. 25.

3.292. g = 1/i 2 (-1)- Bafit, where n = 1, 2,... is the num-

ber of the half-revolution that the loop performs at the given mo-

ment t. The plot g i (t) is shown in Fig. 25 where t„, = V2nn/13.

3.293. /ind = a/r, where a =

3.294. gi_ 4n μu^. 2 s±( I 2 v a a).

3.295. e 1 i / 2 (wa 3 /3 3 + 2mg sin tot)laB.

3.296. v

mgR sin a

B 2 /2 •

3.297. w g sin a.

1 +12B2cim •

3.298. (P) =^1 /^2 (no.ia^2 B)^2 /R.

3.299. B = '1 2 qRINS = 0.5 T.

3.300. q=--

1.;orta inbb+ aa

i.e. is indepen-

dent of L.

3.301. (a) / = 1j 2 ° 51 'v In 1 :;,i 21 ; (b) ; F=i-(1^1 : ln -bw )^2.

3.302. (a) s = vom1111 2 B 2 , (b) Q =^1 .1^2 mv:.

3.303. v= am — (1— e-at), where ar =B 2 / 2 /mR.

3.304. (a) In the round conductor the current flows clockwise,

there is no current in the connector; (b) in the outside conductor,

clockwise; (c) in both round conductors, clockwise; no current in

the connector, (d) in the left-hand side of the figure eight, clockwise.

3.305. I = ,o)B , (a — f b)/p = 0.5 A.

3.306. cm. = 1 / 3 na 2 /1Ta)Bo.

3.307. gi = 3 /2W/ Bt 2 = 12 mV.

3.308. E=

{ 1 / 2 p,onir for r <a,

1 /2I-Lonia^2 /r for r> a.

3.309. I = 1 / 4 1.t onSdi/p = 2 mA, where p is the resistivity

of copper.

3.310. E = 1 /tab (ri — + 1).

3.311. co= — - 2 +- 6 n B (t).

3.312. Ft max fZaRT: b.

3.313. Q = i/ 3 a 2 t 3 /R.

3.314. I =114(b2^ a2) nh/p.

3.315. /=1/-4n/oL/R^0 = 0.10 km.

3.316. L = (^2) 4n - 2 - Ipp (^) o where p and po are the resistivity and the
density of copper.
3.317. t= --R in (1^ = 1.5 s.