Magnetic field and current related questions

1. An initially uncharged capacitor with a capacitance of C= 00 pF is connected in series with resistor with a resistance of R= 4.5 kn. If this series combination of circuit elements is attached to an ideal battery with an emf of f= 450 V by means of a switch S that is closed at time t = 0, then answer the following questions. (a) What is the time constant of this circuit? (b) How long will it take for the capacitor to reach 75% of its final charge? (c) What is the final charge on the capacitor?
2. Chapter 20
3. A long, straight wire in the .r-y plane lies along the z-axis and carries a current of 3.5 A in the -kr An electron is also located in the r-y plane on the y-axis at y = —5.0 cm (r = 0). The electron is moving in the -ky direction (towards the long, straight wire) with a speed of 6.6 n 10° m/s. (a) What is the magnitude and direction of the magnetic field vector due to the long, straight wire at the location of the electron? (b) What is the magnitude and direction of the magnetic force on the electron? (c) Include a diagram of the situation. [Diagram 3 pts.]

 

1. A square loop with 10 turns and a side length of 5.0 cm lies flat on a tabletop. The loop carries a current of 2.0 A that goes counterclockwise when viewed from above while looking down on the table. (a) What is the magnitude and direction of the magnetic moment of the loop? (b) If there is a uniform magnetic field with magnitude 0.75 Tat the location of the loop that heads down through the tabletop and makes an angle of 60° with the surface of the tabletop, then answer the following: (i) what is the magnitude of the net magnetic force on the loop, and (ii) what is the magnitude of the net torque on the loop? (c) Include a diagram of the situation. [Diagram 3 pts.]