Exam 19: Electric Charges, Forces, and Fields

Two point charges each experience a 1-N electrostatic force when they are 2 cm apart.If they are moved to a new separation of 8 cm,what is the magnitude of the electric force on each of them?

Three equal-magnitude point charges of varying signs are placed at three of the corners of a square of side d as shown in the figure.Which one of the arrows shown represents the direction of the net electric field at the vacant corner of the square?

An electron is projected with an initial velocity v₀ = 8.4 × M/s along the y-axis,which is the centerline between a pair of charged plates,as shown in the figure.The plates are 1.0 m long and are separated by 0.10 m.A uniform electric field of magnitude E in the +x-direction is present between the plates.If the magnitude of the acceleration of the electron is measured to be What is the magnitude of the electric field between the plates? (e = 1.6 × 10^-19 C,m_electron = 9.11 × 10^-31 kg)

The figure shows electric field lines arising from two small charged particles P and Q.Consider the following two statements: (i)The charge on P is smaller than the charge on Q. (ii)The electrostatic force on P is smaller than the force on Q. Which of the above statements are true?

As shown in the figure,the charge Q is midway between two other charges.If What must be the charge q1 so that charge q2 remains stationary as Q and q1 are held in place?

An electron is initially moving to the right when it enters a uniform electric field directed upwards,as shown in the figure.Which trajectory (X,Y,Z,or W)will the electron follow in the field?

If a charge generator builds a negative static charge of - 7.00µC. How many electrons are transferred to it during this process.(e = 1.60 × 10^-19C)

Four point charges of equal magnitude but with varying signs are arranged on three of the corners and at the center of the square of side d as shown in the figure.Which one of the arrows shown represents the net force acting on the center charge?

Three equal positive point charges +q are placed at the corners of a square of side d as shown in the figure.Which one of the arrows shown represents the direction of the net electric field at the center of the square?

In outer space,a positive charge q is released near a positive fixed charge Q,as shown in the figure.As q moves away from Q,what is true about the motion of q? (There may be more than one correct choice. )

A small glass bead has been charged to 1.9 nC.What is the strength of the electric field 2.0 cm from the center of the bead? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

Suppose you wanted to hold up an electron against the force of gravity by the attraction of a fixed proton some distance above it.How far above the electron would the proton have to be? (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²,e = 1.6 × 10^-19 C,m_proton = 1.67 × 10^-27 kg,m_electron = 9.11 × 10^-31 kg)

The electric field at a point 2.8 cm from a small object points toward the object with a strength of 180,000 N/C.What is the object's charge q? (k = 1/4πε₀ = 8.99 × 10⁹ N ∙ m²/C²)

A small object with a 5.0-μC charge is accelerating horizontally on a friction-free surface at 0.0050 m/s2 due only to an electric field.If the object has a mass of 2.0 g,what is the magnitude of the electric field?

Two tiny particles having charges of +7.00 μC and -9.00 μC are placed along the y-axis.The +7.00-µC particle is at y = 0.00 cm,and the other particle is at y = 40.00 cm.Where must a third charged particle be placed along the y-axis so that it does not experience any net electric force due to the other two particles?

A conductor is placed in a steady external electric field.Which of the following statements are correct for this situation? (There could be more than one correct choice. )

Three equal-magnitude point charges of varying signs are placed at the corners of a square of side d as shown in the figure.Which one of the arrows shown represents the direction of the net electric field at the center of the square?

Four point charges of varying magnitude and sign are arranged on the corners of the square of side d as shown in the figure.Which one of the arrows shown represents the net force acting on the point charge with a charge +Q?

A negatively-charged rod is brought close to (but does not touch)two neutral spheres that are in contact with each other but insulated from the ground.If the two spheres are then separated,what kind of charge will be on the spheres?

As shown in the figure,three charges are at corners of a rectangle.The charge in the bottom right corner is Q = - 90 nC,and all the other quantities are accurate to two significant figures.What is the magnitude of the net electrical force on Q due to the other two charges? (k = 1/4πε₀ = 9.0 × 10⁹ N ∙ m²/C²)