Please answer all questions. The answers are written right at the end of each question.
1. A proton moves in a circular path perpendicular to a constant magnetic field. If the proton takes 1.00x 10* seconds to go once around the circle, what is the magnitude of the magnetic field? (B = 0.0656T) 2. An electron moves in a straight line at a constant speed of 2.5x10' m/s in a uniform electric field of strength 450 V/m. If the electron is moving along the +x axis and the electric field points along the +y axis, what is the magnitude and direction of the magnetic field? If an *He nucleus (2 protons, 2 neutrons) starts with the same exact velocity (speed and direction) as the electron, what path will it follow? (B-1.80x 10 T, along +z-axis, same path) 3. Two long wires cross each other at the origin of the x-y plane. The wire along the x-axis has a current in the negative x direction of 4.50 A. The wire along the y-axis has a current in the positive y direction of 1.75 A. What is the direction and magnitude of the magnetic field at (3.00, -2.50) cm? At (-3.00. -2.50) cm? 2.43x10"*T, 4.77x10"T along +z 4. The area of a 100 turn coil is .0500m . There is a upward magnetic field of strength 0.200T perpendicular to the plane of the coil. The coil has a resistance of 2.50 ohms. If the magnetic field reverses direction in a time of 0.350 seconds, what is the induced voltage and the induced current? Is the current clockwise or counterclockwise as viewed from above the coil? (AV=5.71 V. 1= 2.29 A) 5. A single wire loop (diameter = 20.0 cm) is stationary in the center of a solenoid with the upward magnetic field of the solenoid perpendicular to the plane of the loop. The loop has a resistance of 1.40 ohms. If the current in the solenoid rise from 2.00 A to 5.50 A in 0.150 second, what is the induced voltage and induced current in the loop? The solenoid has 500 turns and is 10.0 cm long. Is the current clockwise or counterclockwise as viewed from above the coil? (5=4.60x 10" V, I= 3.29x10" A) 6. A neon sign, that requires an RMS voltage of 1 1000V, is plugged into the wall outlet at 120 V RMS. If there are 100 turns in the primary coils for the transformer, how many turns are in the secondary? The power output of the sign is 800 W. What is the secondary RMS current, What is the primary RMS current? Assume a perfect transformer. (N2= 9170, 12 = 72.7 mA, I1 =6.67 A) 7. A capacitor is attached to a 120 V RMS voltage source. The RMS current through the capacitor is 0.750 A. If the capacitor has a value of 4.70 nF, what is the frequency?(f=2. 12x10'/s=212kHz) 8. How much time does it take for a light signal to travel 10.0 km? How much time for sound to travel the same distance? Speed of sound is 340 m/s. (t=3.33x10"s, t=29.4s) 9. The peak electric field in a radio wave of frequency, f =1.01x10 /s, is Eo=0.850 V/m. What is the wavelength of the radio wave? What is the peak magnetic field, Bo? What is the intensity, I, of this wave? () = 2.97 m, Bo = 2.83x10" T, I = 9.59x10* W/m') 1 1. Given the intensity I in the previous problem (1 = 9.59x10* W/m'), and you are 1.50 km from the transmitting radio antenna, what is the power output of the antenna? (P = 27.1 k W)
