MULTIPLE CHOICE 4) A rectangular coil lies flat on a horizontal surface. A bar m

Question

MULTIPLE CHOICE 4) A rectangular coil lies flat on a horizontal surface. A bar magnet is held above the center of the coil 4) with its north pole pointing down. What is the direction of the induced current in the coil? There is no current in thg coil. B) counterclockwise D) Not enough information is provided. C) clockwise 5) A u niform ma gnetic field is applied perpendicular to the plane of a 60-turn circular coil with a 5) radius of 6.0 cm and a s, what is the emf induced in that coil? resistance of 0.60 ? If the magnetic field increases from 0.20 T to 1.8 T in 0.20 A) 7.2 V B) 5.4 V C) 9.2V D) 0 V E) 12 V 6) The primary coil of a transformer has 100 turns and its secondary coil has 400 turns. If the ac current in the secondary coil is 2 A, what is the current in its primary coil? A) 2 A B) 4 A C) 1/2 A D) 8 A E) 1/4 A 7) The capacitive reactance of a 44-uF capacitor in an ac circuit is 6.0 x 102 ? what is the frequency of the applied signal? A) 6.0 Hz B) 80 Hz C 800 Hz D) 17 Hz E) 2.2 Hz 8) A 120-V rms voltage at 60.0 Hz is applied across an inductor, a capacitor, and a resistor in series. If the rms value of the current in this circuit is B00 A, what is the impedance of this circuit? A)200 ? B) 100 C)141 ? D) 1200 E)20 4 ? mS 9) A 60.0-W light bulb radiates light uniformly in all different directions. What is the value of B at a distance of 0.700 m from the bulb? A) 2.02 x 10-7T B) 1.76 x 10-7 T C) 4.86 × 10-7 T D) 2.22 x 10-7T E) None of the other answers is correct

Explanation / Answer

Solution:

5) induced emf (e) = N * d (B * A) /dt

=> e = 60 * 3.14 * (0.06)^2 * (1.8 - 0.2 ) / 0.2

=> e = 5.42592 V

So induced emf = e = 5.4 V option B

6) Is / Ip = Np / Ns (Is and Ip are current in secodnary and primary coil respecitvely)

=> Ip = Is * Ns / Np

=> Ip = 2 * 400 / 100

=> Ip = 8 A

7) Capacitive reactance Xc = 1 / w * C (w is angular frequency)

=> w = 1 / Xc * C

=> w = 10^6 / 44 * 6 * 10^2

=> w = 10000/(44 * 6)

=> w = 37.87 rad/s

Now 2 * pi * f = 37.87

=> f = 6 Hz option A

8) Z (impredence) = V / I

=> Z = 120/0.6

=> Z = 200 ohm (option A)

9) Using I = c ( B^2 / u0)

c is speed of light , u0 is permiability , I = P / Area ,

Using the above equation,

we get B = 2.02 * 10^-7 T

option A .

please comment for Queries

Please rate thanks.

Related Questions

Navigate

• Browse (All)
• Browse M
• Subjects

---

---

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