Class Examples from Chapter 30

Class Examples from Chapter 30 - Class Examples from...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Class Examples from Chapter 30 12. To have an induced emf, the magnetic field must be perpendicular (or have a nonzero component perpendicular) to the coil, and must be changing with time. (a) For 2 ˆ (4.00 10 T/m) k By  , /0 dB dt and hence = 0. (b) None. (c) For 2 ˆ (6.00 10 T/s) k Bt , = d Φ B dt = A dB dt = (0.400 m × 0.250 m)(0.0600 T/s) = 6.00 mV, or | | = 6.00 mV. (d) Clockwise. (e) For 2 ˆ (8.00 10 T/m s) k B yt , B = (0.400)(0.0800 t ) ydy = 3 1.00 10 t , in SI units. The induced emf is / 1.00 mV, d B dt    or | | = 1.00 mV. (f) Clockwise. (g) 0 0 B   . (h) None. (i) 0 0 B   . (j) None. 13. The amount of charge is 32 2 1 1.20 10 m ( ) [ (0) ( )] [ (0) ( )] [1.60T ( 1.60T)] 13.0 2.95 10 C . BB A q t t B B t RR    14. Figure 30-40(b) demonstrates that / dB dt (the slope of that line) is 0.003 T/s. Thus, in absolute value, Faraday’s law becomes
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
() B d d BA dB A dt dt dt       where A = 8 ×10 4 m 2 . We related the induced emf to resistance and current using Ohm’s law. The current is estimated from Fig. 30-40(c) to be i = / dq dt = 0.002 A (the slope of that line). Therefore, the resistance of the loop is 42 | | | / | (8.0 10 m )(0.0030 T/s) 0.0012 0.0020 A A dB dt R ii . 17. Equation 29-10 gives the field at the center of the large loop with R = 1.00 m and current i ( t ). This is approximately the field throughout the area ( A = 2.00 10 4 m 2 ) enclosed by the small loop. Thus, with B = 0 i /2 R and i ( t ) = i 0 + kt , where i 0 = 200 A and k = ( 200 A 200 A)/1.00 s = 400 A/s, we find (a)       7 4 00 4 10 H/m 200A ( 0) 1.26 10 T, 2 2 1.00m i Bt R  (b)        7 4 10 H/m 200A 400A/s 0.500s ( 0.500s) 0, 2 1.00m   and (c)        7 4 4 10 H/m 200A 400A/s 1.00s ( 1.00s) 1.26 10 T, 2 1.00m   
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/18/2011 for the course PHY 108 taught by Professor Iashvili during the Fall '08 term at SUNY Buffalo.

Page1 / 5

Class Examples from Chapter 30 - Class Examples from...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online