# Physics

posted by Annoyingmous

An infinite straight wire carrying a current I=5 A flowing to the right is placed above a rectangular loop of wire with width w=11 cm and length L=27 cm, as shown in the figure below. The distance from the infinite wire to the closest side of the rectangle is h=1.7 cm. The loop of wire has resistance R=0.31 Ohm.

(a) What is the magnitude (in Tesla) of the magnetic field due to the infinite wire at the point P in the rectangular loop, a distance r=3.2 cm from the wire (see figure).

In which direction does it point?

(b) Calculate the magnitude of the magnetic flux (in Tesla  m2) through the rectangular loop due to the magnetic field created by the infinite wire.

(c) Suppose the current in the infinite wire starts increasing in time according to I=bt, with b=50 Amps/sec. What is the magnitude (in Amps) of the induced current in the loop? Neglect any contribution to the magnetic flux through the loop due to the magnetic field created by the induced current.

(d) What is the direction of this current flow?

1. ^_ ^

a) B = mu_0*I/(2*Pi*r)

b) phi = (mu_0*I*L/(2*Pi))*ln(1+w/h)

c) i = (-1/R)*(mu_0*L)/(2*Pi)*ln(1+w/h)*(di/dt)

2. Phy

What is di/dt ??

3. Anonymous

Phy, it's the b in the variation I=bt. Just use the b value in the problem for (di/dt)

4. Phy

Thanks, can u tell me the solutions of 1,4,6,9,10,11,12?

5. dd

the C is wrong for me using the b in di/dt

6. robbo

Have you guys gt 3,5,7,8,9,10,11,12...????? Let's help each other and get this done guys!!

7. Sat

C is wrong ...

8. boss

Some people haven't done even one question.

9. boss

I wonder if some people understand the subject at all. It is an insult to the lecturer.

10. Sat

Hey boss, how did u come across this topic if you have not googled the question? It's obvious that you cheat also!

BTW - for C just use the value for b (the one in the question) b=(di/dt)

11. Anonymous

Hey guys, what abput prob. 10?

12. BG

10, b) how to solve

13. Jack

14. robbo

Problems 8-12 guys, please???/

15. P

Please tell ans of any question please
Q3 a=0 last part =0

16. BG

Anyone, can help with questions:

11 c)
10 b)
8 d,e,f)
5 b,d,e)

17. BG

11 a)
q/(4*pi*E_0*(r^2)*k)

11 b)
q*k/(r^2)

11 d) 0

18. me

anyone for question 7 please

19. Jack

Hi BG, can you put the results for 8 a, b,c?

20. AAA

21. AAA

anyone for question 3 please??????

22. Jack

5 e)
v= m*g*R/(B^2*W^2)

23. BG

8 a)
E = (st)/(S*E_0)
S = Area

8 b) E*d

8 c)
C = E*E_0*S/d

24. BG

S = pi(b^2 - a^2)

25. BG

Jack, did you solve anything else from this list:
11 c)
10 b)
8 d,e,f)
5 b,d)

26. BG

me, I will exchange solution 8 on 7)

27. BG

me, a = lambda/0.5
d = lambda/0.125

28. BG

denaminator may be different, it depends on drawing

29. AAA

How I can know my denominator watching my grahp BG?

30. BG

prob 8

31. BG

I think drawings at all identical so don't worry

32. me

BG sorry don't have 8 yet, i'll post it as soon as i solve it and thanks for 7

33. me

i have 5 do you still need 5b and 5d

34. Jack

BG,

8 d)

B= mu_0*(r^2-a^2)*s/(2*r*pi*(b^2-a^2))

35. Jack

BG, do you have 10 c and d?

36. AAA

Please me, question 5

37. OVNI

8 e)
t*s^2/2*PI^2*(b^2-a^2)

Please anyone 10 and 9c)

38. me

5) a)=B(l-W)z(t)
b)=(B*V*W)/R
c)=(B^2*V*W^2)/R
d)= (M*g*R)/(B^2*W^2)

39. Jack

Please OVNI, 11 c)

40. Jack

8 f)
Result of e multiplied by 2*pi*b*d

41. robbo

i'm conufsed about the parentheses that might havve been omitted in OVNI's answer to 8e....

t*s^2/(2*PI^2*(b^2-a^2) )

Is this correct?

42. Jack

I think a b is missing!

t*s^2/(2*PI^2*b*(b^2-a^2) )

43. OVNI

Sorry, it's

(t*s^2)/(2*PI^2*b*(b^2-a^2))

Please, anyone 9c) and 10c)

44. robbo

8f, 8e solutions aren't working out as given by OVNI and Jack... help guys?

45. Jack

Please 11 c) and 10!

46. robbo

Jack, 11c is 0.5*L*I^2

47. AAA

Thank you so much!
Question 10??

48. OVNI

Sorry, but I posted as I worked and I got a green check mark.
Please any one 9 and 10

49. robbo

Sorry I meant 10c is 0.5*L*I^2.... the LC circuit sum, does anybody have 10 b and d??

50. robbo

how do you get 11 b and c???

51. OVNI

Roboo, why in your 11c you use L, and I?????

52. robbo

I meant 10c OVNI! Mistake... SOrry!

53. OVNI

Please 10d) and 9c)

54. robbo

9b????

55. Jack

robbo, the same that 9 a)

56. 124

9b = 9a, E1 = V/d1 and E2 = V/d2

9c)try with charge conservation

57. Jack

robbo 10 b)

58. BG

11 b)
q*9*(10^9)/r^2
r = distance from the origin

59. Jack

10 b) 10 d) and 11 c) please!!!!

60. w

5A doesn't seem to work

61. P

Please give ans for Q5 for values I am getting them last chance please

What is the total magnetic flux through the loop (in Tesla m ) when is 62 cm. Include only the magnetic flux associated with the external field (i.e. ignore the flux associated with the magnetic self-field generated by the current in the wire loop). Note that you do not need to calculate or know at what time the loop is at this location.

incorrect

(b) Using Faraday's Law and Ohm's Law, find the magnitude (in Amps) of the induced current in the bar at the time when 1.00 m/sec. Note that you do not need to calculate or know at what time the loop has this speed.

incorrect

(c) Which way does the current flow around the loop, clockwise or counterclockwise?

Status: correct

(d) What is the total magnetic force (in Newtons) on the rigid wire loop when 1.00 m/sec? Again, ignore any effects due to the self magnetic field.

direction:
Status: correct

magnitude (in Newtons):

incorrect

(e) What is the magnitude of the terminal speed (in m/sec) of the loop (i.e. the speed at which the loop will be moving when it no longer accelerates)?

62. BG

8 e)

poling vector = E*B/mu_0 = ??

63. BG

it's correct ?

64. 124

P, phi=B*w*(L-z)
|em|=|dphi/dt|=B*w*V
i=|em|/R=B*w*V/R
F=watt/ms^-1=(|em|^2/R)*1/V

65. 124

BG, OK

66. Jack

67. 124

10b)= frequency that abs(i(t))=max

68. Jack

f= 1/(2*pi*sqrt(L*C))?

69. Jack

and 10 d), please

70. 124

i(t)=I0*cos(w*t) and abs(i(t))=max if
w*t=k*pi, for k=1=>t1=pi/w
f=1/t1=w/pi=1/(pi*sqrt(L*C))

71. BG

124, i have E and B correct
but

pointing vector with formula E*B/mu_0, mu_0 = 4*pi*10^(-7), incorrect.

pliz, tell where is error?

72. 124

10d)=>average p=v*i on [0,3*t1]

73. 124

BG, S=E*B/mu_0
= 1/(2*pi^2*b)*s^2*t/(b^2-a^2)

74. 124

10b) f=1/t1=w/pi=1/(pi*sqrt(L*C))

75. 124

BG, B(r=b) = mu_0*s/(2*pi*b)is not the the previous B(r)

76. BG

124, thanks a lot, you the man. )

77. BG

124, 11 c) - Could you please help and give any hints on it?

78. Jack

79. robbo

in 10d for P=V*I, where do we get V from???

80. 124

robbo, v=Ldi/dt
P_mean=1/(3T-0)*int(v*i,0,3*T)
T=2*pi*sqrt(L*C)

11c)e)=>Q_net+ q = Q_encl in the gauss Law

81. robbo

S=E*B/mu_0
= 1/(2*pi^2*b)*(s^2)*(t/(b^2-a^2))

What's wrong with this formula guys??

82. Jack

(t*s^2)/(2*(PI^2)*b*(b^2-a^2))

83. 124

robbo, formula is right, check s^2*t
for example s=24u and t=5u
s^2*t = 24*24*5*1u^3

84. Jack

10 d) Positive or negative?

85. Jack

Is this correct for 10 d)=

P=1/3T * int(-L*w*(Imax)^2*sin(wt)*cos(wt), 0 , 3T)
Thanks!!!

86. robbo

Jack, and 124, for the formula:(t*s^2)/(2*(PI^2)*b*(b^2-a^2)) = 5.27300181668e-11

at s=12uC/sec, t=1usec, b=0.0053m, a=0.0014m

I've followed the formula, but the answer shows wrong... I hope you guys can help?

87. robbo

Jack, the formula you've used is correct :)

88. robbo

Q11 formulae, anybody??

89. 124

Jack, yes the formula is OK

90. robbo

124, I have no idea what on earth I'm doing wrong, followed your formula... and input values and got the same answer everytime I tried, apparently its incorrect! :( Can you input my values and see what answer you get?

91. 124

robbo,sorry i forgot e_0
(1u*12u^2)/(2*(PI^2)*5.3m*(5.3m^2-1.4m^2)*8.85e-12) =5.95215457341
E =|E|er
|E|=1/(4*pi*e_0*kappa)*q/r^2 for (a<r<b) |E|=1/(4*pi*e_0)*q/r^2 for r>=b

92. 124

S=E*B/mu_0
= 1/(2*pi^2*b*epsilon_0)*(s^2)*(t/(b^2-a^2))

93. 124

guys, you can subscribe in the new course ReView (8.MReVx)

94. 124

10d)
P=1/3T * int(-L*w*(Imax)^2*sin(wt)*cos(wt), 0 , 3T) = 0!!!!!

T=2*pi*sqrt(L*C)

95. robbo

124, i think its supposed to be t^2/(b^2-a^2) instead of t to the power of 1.

96. robbo

9c, 11c anybody?

97. Jack

11 c) Is the net charge positive or negative?

98. MIT

THIS IS CHEATING!!! YOU ARE NOT FOLLOWING THE HONOUR CODE!!

99. HarvardX

Dear MIT, you got here by???? Googling for what?

100. l

101. Jack

102. 124

it seems that we cheated. So I leave. Good luck to all!

## Similar Questions

1. ### Physics

A 2.00 cm x 2.00 cm square loop of wire with resistance 1.30×10^−2 Ohms is parallel to a long straight wire. The near edge of the loop is 1.00 cm from the wire. The current in the wire is increasing at the rate of 110 A/s. What …
2. ### physics

A long straight wire is oriented in the z direction and carries a current I. A square loop with sides of length w is in the xz-plane with its nearest edge a distance d from the wire. In time of t, the square loop moves a distance of …
3. ### Physics

Would someone check this please? A circular loop of wire of radius 0.10 m and of resistance 2.0 ~ 10−3 ƒ¶ is in a region where there is a uniform magnetic field B. The field is at 30‹ to the normal to the plane of the
4. ### Physics

Would someone check this please? A circular loop of wire of radius 0.10 m and of resistance 2.0 x 10^−3 ohms is in a region where there is a uniform magnetic field B. The field is at 30deg to the normal to the plane of the wire
5. ### Physics

Would someone check this please? A circular loop of wire of radius 0.10 m and of resistance 2.0 x 10^−3 ohms is in a region where there is a uniform magnetic field B. The field is at 30deg to the normal to the plane of the wire
6. ### physics

A long, vertical, straight wire carries a current I going upwards. The wire is perpendicular to the plane of a circular metal loop and passes through the center of the loop. The loop is allowed to fall and maintains its orientation …
7. ### Physics

A rectangular loop of wire, L = 26.2 cm and W = 15.4 cm, carries a I1 = 1.83 A current and lies in a plane (d = 13.6 cm), which also contains a very long straight wire carrying a I2 = 10.5 A current. I used this equation: F1+F2 = mu0*I1*I2*0.262/(2pi)*(1/0.136-1/0.290)=2.57*10^-7 …
8. ### physics

A long, straight wire has a 12.1 A current flowing in the positive x-direction, as shown in the figure. Close to the wire is a square loop of copper wire that carries a 2.23 A current in the direction shown. The near side of the loop …
9. ### Physics

An infinite straight wire carrying a current I=5 A flowing to the right is placed above a rectangular loop of wire with width w=11 cm and length L=27 cm, as shown in the figure below. The distance from the infinite wire to the closest …
10. ### physics

A rectangular loop of wire is placed next to a straight wire, as shown in Fig. 20–55. There is a current of 3.5 A in both wires. Determine the magnitude and direction of the net force on the loop

More Similar Questions