Answer: Last Answer: 0.864 V Not yet correct, tries 1/20 Hint: When the magnetic

Question

Answer:  Last Answer: 0.864 V
Not yet correct, tries 1/20

Hint: When the magnetic field is uniform and normal to the plane of the loop, then the flux is of the product of the field and the area. In this problem it is the area that changes with time, not the field.

7. [2pt]
The emf around the loop causes a current to flow. How large is that current? (Again, use a positive value for clockwise direction.)

Answer:  Last Answer: 22.685 A
Not yet correct, tries 1/20

Hint: Remember F=ma: since v is constant, a=0, so it must be true that the net force on the rod is zero. The pulling force is compensating the force on the rod due to the current through it and the magnetic field.

10. [2pt]
A generator is constructed by rotating a coil of N turns in a magnetic field B at a frequency f. The internal resistance of the coil is R and the cross sectional area of the coil is A.
Which of the following statements are true? (Give ALL correct answers, i.e., B, AC, BCD...)

A) The average induced EMF doubles if the frequency f is doubled.
B) The average induced EMF doubles if the area A is doubled.
C) The maximum induced EMF occurs when the coil is rotated about an axis parallel to the magnetic field lines.
D) The maximum induced EMF occurs when the coil is rotated about the axis of the coil.
E) The average induced EMF doubles if the magnetic field B is doubled.
F) The average induced EMF doubles if the resistance R is doubled.

Answer:  Last Answer: ABCE

Explanation / Answer

induced emf = VBL = VBd = 4 *  0.60*0.36 = - 0.864 V

F = i L*B

i = F/ L*d = 4.9 / ( 0.36* 0.60) = - 22.68 A

induced emf

E = BANsin = BANsin(t)

= 2pi *f

so correct answers are

A) The average induced EMF doubles if the frequency f is doubled.

B) The average induced EMF doubles if the area A is doubled

D) The maximum induced EMF occurs when the coil is rotated about the axis of the coil.

E) The average induced EMF doubles if the magnetic field B is doubled.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.