24. Electric Force & Field; Gauss' Law

For a point charge located at the origin, what is the radial component of the electric field at a distance $r$ from the charge?

An electric field at a point in space is defined as the force per unit charge experienced by which type of particle placed at that point? $E=\frac{F}{q}$

Consider two point charges: a $10\mathrm{nC}$ charge and a $20\mathrm{nC}$ charge placed a certain distance apart on a straight line. Is there a point between them where the net electric field is zero?

Consider two point charges of equal magnitude but opposite sign placed a distance $d$ apart along the x-axis, as shown in Figure 1(a). At which point or points along the line joining the charges is the electric field zero?

Which of the following actions will increase the strength of the electric force between two point charges according to $F=\frac{k{q}_1{q}_2}{r^2}$ (Coulomb's law)?

A point charge of magnitude $q$ is placed at the center of a cube with sides of length $l$. What is the total electric flux through the entire surface of the cube?

Can an object with $no net charge$ produce an $electric field$?

A point charge of $5.0\times {10}^{-6}C$ is located at the origin. Calculate the magnitude of the electric field at point A, located at coordinates $(0,12.0)$ meters. (Assume vacuum, $k=8.99\times {10}^{9}N\cdot m^2/C^2$.)

A thin spherical shell of radius $r_1$ carries a total charge $Q$. Another concentric thin spherical shell of radius $r_2$ ($r_2>r_1$) carries no charge. What is the magnitude of the radial electric field at the point $r=0.5(r_1+r_2)$? Give your answer in units of $kN/C$.

What is the magnitude of the electric field at a distance $r$ from a thorium nucleus (atomic number $90$)? Assume the nucleus is a point charge and use $k$ for Coulomb's constant and $e$ for the elementary charge.

Which of the following electric field line diagrams is incorrect for isolated point charges?

A 1.5μC charge, with a mass of 50g, is in the presence of an electric field that perfectly balances its gravity. What magnitude does the electric field need to be, and in what direction does it need to point?

At point $p$, which is located near a positive point charge, what is the direction of the electric field at this point?

Suppose two points, point 1 and point 2, are located at different distances from a single positive point charge. What can you say about the magnitude of the electric field at point 1 compared with the field at point 2?$E$ at point 1 compared with $E$ at point 2?