24. Electric Force & Field; Gauss' Law

Two point charges, $q_a$ and $q_b$, are separated by a distance $r$. What is the magnitude of the net electric force on charge $q_a$ due to charge $q_b$?

How does the electric current produced by an $AC$ generator differ from that produced by a $DC$ generator?

In a circuit containing three resistors connected in parallel to a single voltage source, how many potentially different currents can exist in the circuit?

In the circuit shown in (figure 1), a capacitor is connected in series with a resistor and a battery. The switch has been closed for a long time prior to $t=0$, allowing the circuit to reach steady state. What is the charge stored on the capacitor just before $t=0$?

Which of the following best describes an $RC$ circuit in the context of electric charge?

For a long hollow cylindrical conductor carrying a steady current, what is the electric field inside the hollow region (but not inside the conducting material itself)?

Which of the following units is used to measure electrical resistance?

In electrostatics, if a conductor is placed in an external electric field and is in equilibrium, what is the total surface charge $q_{\mathrm{ext}}$ on the exterior surface of the conductor?

Which device is typically used to produce alternating current?

Two point charges are placed on the x-axis: charge $q_1$ at $x=0$ and charge $q_2$ at $x=d$. If both charges are positive, what is the direction of the net electric force on $q_1$ due to $q_2$?

In the context of electric charge and semiconductor devices, what type of bias is applied to a $pn$ junction if the cathode is positive with respect to the anode?

Which of the following statements about the flow of electricity through air is correct?

Two point charges, $q=8.0\mathrm{nC}$ and $Q=12.0\mathrm{nC}$, are separated by a distance of $r=0.50m$ in vacuum. What is the magnitude of the force $F$ on the $8.0\mathrm{nC}$ charge?

A current of $0.50A$ flows through a resistor of $820\Omega$. What is the voltage across the resistor?

Which of the following factors does not affect the resistance of a conductor?