24. Electric Force & Field; Gauss' Law

Two point charges, a positive charge $+q$ and a negative charge $-Q$, are placed on a straight line with a point (the dot) between them. If the electric field at the dot is zero, what is the value of the negative charge $-Q$ in terms of $q$ and the distances $a$ (from $+q$ to the dot) and $b$ (from $-Q$ to the dot)?

Which property makes a metal a good material to use for electrical wires?

In the context of electric charge and current, the length of time that current is flowing is known as:

Why do metals often make good conductors of electric charge $q$?

In the context of electric motors, what is the primary purpose of a commutator?

Alternators induce voltage by rotating which of the following components?

Which characteristic is common to all electrical insulators?

How many electrons make up −1.5 × 10⁻⁵ C?

How many electrons do you have to add to decrease the charge of an object by 16 μC?

Two small aluminum spheres, each having mass $0.0250$ kg, are separated by $80.0$ cm. How many electrons does each sphere contain? (The atomic mass of aluminum is $26.982$ g/mol, and its atomic number is $13$.)

What mass of aluminum has a total nuclear charge of $1.0$ C? Aluminum has atomic number $13$.

What is the total charge of all the electrons in $1.0$ L of liquid water?

If a proton and an electron are released when they are $2.0\times {10}^{-10}$ m apart (a typical atomic distance), find the initial acceleration of each particle.