Exam 19: Dc Circuits

The coil of an ac generator has 50 loops and a cross-sectional area of $0.25 \mathrm {~m} 2$ . What is the maximum emf that can be generated by this generator if it is spinning with an angular speed of $4.0 \mathrm { rad } / \mathrm { s }$ in a $2.0$ - T magnetic field?

A resistance of $55 \Omega$ , a capacitor of capacitive reactance $30 \Omega$ , and an inductor of inductive reactance $30 \Omega$ are connected in series to a $110 - \mathrm { V }$ rms $60 - \mathrm { Hz }$ power source. What rms current flows in this circuit?

A bar magnet is close to a solenoid, as shown in the figure. As viewed through the solenoid looking toward the magnet, what is the direction (clockwise or counterclockwise) of the current (if any) induced in the solenoid in each case? (a) The magnet is pushed toward the solenoid. (b) The magnet and solenoid both move to the right at 25 cm/s.

Four resistors having resistances of $20 \Omega , 40 \Omega , 60 \Omega$ , and $80 \Omega$ are connected in series across an ideal dc voltage source. If the current through this circuit is $0.50 \mathrm {~A}$ , what is the voltage of the voltage source?