Exam 20: Electric Potential and Electric

When a certain capacitor carries charges of ±10 µC on its plates,the potential difference cross the plates is 25 V.Which of the following statements about this capacitor are true? (There could be more than one correct choice. )

A proton and an electron are released from rest,with only the electrostatic force acting.Which of the following statements must be true about them as they move toward each other? (There could be more than one correct choice. )

Four charged particles (two having a charge +Q and two having a charge -Q)are arranged in the xy-plane,as shown in the figure.These particles are all equidistant from the origin.The electric potential (relative to infinity)at point P on the z-axis due to these particles,is

Two protons are released from rest,with only the electrostatic force acting.Which of the following statements must be true about them as they move apart? (There could be more than one correct choice. )

Consider a uniform horizontal electric field of 50 N/C directed toward the east.If the electric potential at a given point in the field is 80 V,what is the potential at a point 1.0 m directly east of the point?

An air-filled 20-μF capacitor has a charge of 60 μC on its plates.How much energy is stored in this capacitor?

If you want to store 2.0 mJ of energy in a 10-μF capacitor,how much potential do you need to put across it?

Point charges +4.00 μC and +2.00 μC are placed at the opposite corners of a rectangle as shown in the figure.What is the potential at point B due to these charges? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

A proton with a speed of 2.0 x M/s accelerates through a potential difference and thereby increases its speed to 4.0 × M/s.Through what magnitude potential difference did the proton accelerate? ,m_proton = 1.67 × 10^-27 kg)

When a 4-μF capacitor has a potential drop of 20 V across its plates,how much electric potential energy is stored in this capacitor?

Four 2.0-µC point are at the corners of a rectangle with sides of length 3.0 cm and 4.0 cm.What is the electric potential (relative to infinity)at the midpoint of the rectangle? (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)

A uniform electric field,with a magnitude of 500 V/m,is points in the +x direction.If the potential at Is 2500 V,what is the potential at ?

A capacitor has a voltage of Applied across its plates,and then the voltage source is removed.What is the potential difference across its plates if the space between them is then filled with mica,having a dielectric constant of 5.4?

Four charged particles (two having a charge +Q and two having a charge -Q)are arranged in the xy-plane as shown in the figure.The charges are all equidistant from the origin.The amount of work required to move a positively charged particle from point P to point O (both of which are on the z-axis)is

Three point charges,-2.00 μC,+4.00 μC,and +6.00 μC,are located along the x-axis as shown in the figure.What is the electric potential (relative to infinity)at point P due to these charges? (k = 1/4πε₀

A 3.0-pFcapacitor consists of two large closely-spaced parallel plates that have surface charge densities of If the potential across the plates is 23.0kV. With only air between them,find the surface area of each of the plates.(ε₀ = 8.85 × 10^-12 C²/N ∙ m²)

At a distance d from a point charge Q,the energy density in its electric field is u.If we now go to a distance d/2 from the charge,what is the energy density at the new location?

The potential (relative to infinity)at the midpoint of a square is 3.0 V when a point charge of +Q is located at one of the corners of the square.What is the potential (relative to infinity)at the center when each of the other corners is also contains a point charge of +Q?

A 7.0-μC point charge and a Point charge are initially extremely far apart.How much work does it take to bring the Point charge to the point ,and the Point charge to the point (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)

A +3.0-µC point charge is initially extremely far from a positive point charge Q.You find that it takes 41 J of work to bring the +3.0-µC charge to the point x = 3.0 mm,y = 0.0 mm and the point charge Q to the point x = -3.0 mm,y = 0.00 mm.What is Q? (k = …)