24. Electric Force & Field; Gauss' Law

Two small spheres spaced $20.0$ centimeters apart have equal charge. If the force between them is measured to be $2.0\times 10{\mathrm{-6}}^2$ newtons, what is the magnitude of the charge on each sphere? (Assume the spheres are in vacuum and use $k=8.99\times 109^9$ N·m$2^{-}$/C$2^2$.)

Which of the following correctly describes the electric force between an $e-$ (electron) and a $p+$ (proton), and between two $e-$ (electrons)?

An electric current is defined as the flow of what through a conductor?

A large lightning bolt had a current of $\mathrm{20,000} A$ and moved a charge of $30.0 C$. What was the duration of the lightning bolt?

A spherical shell contains three charged objects with charges $q_1$, $q_2$, and $q_3$. What is the total electric flux through the surface of the shell according to Gauss's law?

Which unit is used to measure $R$ (resistance)?

Suppose an electric field exerts a westward force on an electron. In which direction is the $E$ field at the location of the electron?

Which of the following is the SI unit of electric current?

Which of the following is an advantage of using a noncontact voltage detector compared to a voltmeter when testing for the presence of electric charge in a wire?

In an electric circuit, the negative pole ($-$) and positive pole ($+$) at the ends of the circuit are known as:

Which combination of two wire properties would provide the greatest resistance to the flow of a current?$R=\rho \frac{L}{A}$

In an electric motor, what is the primary role of $\mathrm{electric charge}$?

Which of the following is the main disadvantage of parallel circuits?

Suppose three point charges are arranged at the vertices of an equilateral triangle. If each charge has magnitude $q$ and the side length of the triangle is $a$, what is the magnitude of the net electric force on one of the charges due to the other two?

A circuit contains a resistor and a capacitor in series with a battery. At time $t=0$ s, the current is $i_0$. At what time in $\mu s$ will the current decrease to $\frac{1}{2}{i}_0$?