⚡ Electric Charge & Force — Unit Quiz

Two rubber balloons are each rubbed with wool and brought near each other. They will:

An object gains 3 extra electrons (e = 1.6×10⁻¹⁹ C). What is the net charge of the object?

Two point charges q₁ and q₂ separated by distance d exert force F on each other. If both charges are doubled (2q₁ and 2q₂), the force becomes:

Electric field lines always point:

Select ALL true statements about electric field lines.

Calculate the electric force between q₁ = 4×10⁻⁶ C and q₂ = 2×10⁻⁶ C separated by 0.3 m. (k = 9×10⁹ N·m²/C²)

A charge of +3×10⁻⁶ C is placed in a uniform electric field E = 4000 N/C pointing east. What is the electric force on the charge?

A neutral metallic sphere is brought close to (but not touching) a positively charged rod. What happens to the charge distribution on the sphere?

Two identical conducting spheres touch: Sphere A has charge +8 μC and Sphere B has charge −2 μC. After separation, what is the charge on each sphere?

Select ALL correct statements about a metallic conductor in electrostatic equilibrium.

Three charges on the x-axis: +4 μC at x = 0, −2 μC at x = 0.2 m, and +3 μC at x = 0.4 m. What is the net force on the +3 μC charge? (k = 9×10⁹ N·m²/C²)

The electric field at point P due to a +5×10⁻⁶ C charge is 45,000 N/C. How far is P from the charge? (k = 9×10⁹ N·m²/C²)

A small positive test charge q₀ is used to map an electric field at various points. Select ALL correct statements about how E is defined.

Two charges: q₁ = +6×10⁻⁶ C at the origin and q₂ = −4×10⁻⁶ C at x = 0.3 m. (k = 9×10⁹ N·m²/C²) (a) Find the magnitude and direction of the electric force on q₂. (b) At what point on the x-axis to the RIGHT of x = 0.3 m is the total electric field zero? (Set up the equation; you do not need to solve algebraically.)

Two equal positive charges q = +3×10⁻⁶ C are placed on the x-axis at x = 0 and x = 0.6 m. (k = 9×10⁹ N·m²/C²) (a) Find the magnitude of the force between the charges. (b) Find the location on the x-axis where the total electric field is zero and explain your reasoning. (c) If a negative charge −q₀ is placed at that point, describe its equilibrium (stable or unstable?) and explain.