AP Physics-T1

Two charged particles, 𝑄1 = + 12.0 𝑚𝐶 and 𝑄2 = −5.0𝑚𝐶 are placed on a line. At what finite locations along the line may the electric potential be equal to zero?
I.  in between the particles, closer to the positive particle
II.  in between the particles, closer to the negative particle III.  not in between, but closer to the positive particle
IV.  not in between, but closer to the negative particle

• I only 
• II only   
• IV only     
•  II and IV only

Tags

NGSS.HS-PS3-5

NGSS.HS-PS2-4

The electric field in a region of space is given by the function 𝐸 = −30𝑥 + 2, where 𝑥 is in meters and 𝐸 is in volts/meter. What is the electric potential at 𝑥  = 2𝑚, relative to the origin?

• +56 V
• +60 V
• –30 V
• –56 V

Three equal point charges +𝑞 are placed at the vertices of an equilateral triangle of side length 𝑎. calculate the potential at the center of the triangle at 𝑃.

• 3√3𝑄/ 2𝜋𝜀_o𝑎
• 3√3𝑄/ 4𝜋𝜀_o𝑎
• √3𝑄/ 2𝜋𝜀_o𝑎
• 3𝑄/ 2𝜋𝜀_o𝑎

A light, rigid, insulating rod of length L is free to rotate vertically about a horizontal axis at one end. At the other end of the rod, a charged sphere of mass m and charge –Q is mounted. The rod is released in a horizontal position as shown above while an electric field is applied in the vicinity of the sphere. What magnitude and direction of the field is required to maintain the sphere-rod in the horizontal orientation?

•     𝑚𝑔 /𝑄, up
•  𝑚𝑔 /𝑄, down
•  𝑚𝑔L /𝑄, up
•  𝑚𝑔L /𝑄, down

For the set up shown, which statement concerning the point P is true?

• The potential is zero and the field is to the right.
• The potential is zero and the field is to the left   
• The potential is negative and the field is zero   
• The potential is positive and the field is zero

Tags

NGSS.HS-PS3-5

NGSS.HS-PS2-4

The graph in the figure shows the variation of the electric potential 𝑉(𝑥) (in arbitrary units) as a function of the position 𝑥 (also in arbitrary units). Which of the choices below correctly describes the orientation of the x-component of the electric field along the 𝑥 −axis?

• 𝐸_k is positive from 𝑥 = −2 𝑡𝑜 𝑥 =  2 
• 𝐸_k is negative from 𝑥 = −2 𝑡𝑜 𝑥 = 2 
• 𝐸_k is positive from 𝑥 = −2 𝑡𝑜 𝑥 = 0, and negative from 𝑥 = 0 𝑡𝑜 𝑥 = 2 
• 𝐸_k is negative from 𝑥 = −2 𝑡𝑜 𝑥 = 0, and positive from 𝑥 = 0 𝑡𝑜 𝑥 = 2

Three charges of −2.00µ𝐶, +4.00µ𝐶 𝑎𝑛𝑑 + 6.00µ𝐶 are placed along the 𝑥 −axis as shown in the figure. What is the electrical potential at point P (relative to infinity) due to these charges?

• 0 𝑘𝑉 
• −154 𝑘𝑉 
• −307 𝑘𝑉 
• +307 𝑘𝑉

Determine the electric filed at point P from the two point charges both of charge +𝑄, with one point charge being a distance 𝑅 and the other being a distance 2𝑅.

• 3𝑞 /16𝜋𝜀_o𝑅²
  
• 2𝑞 /16𝜋𝜀_o𝑅²
• 3𝑞 /4𝜋𝜀_o𝑅²
• 2𝑞 /4𝜋𝜀_o𝑅²

Three charges all of +𝑞 are brought together so that they form an equilateral triangle, with a distance 𝑟 between them. Determine the electrostatic potential energy needed to bring the system together from infinity.

• 3𝑞^2/4𝜋𝜀_o𝑟
• 𝑞^2/2𝜋𝜀_o𝑟
• 2𝑞^2/4𝜋𝜀_o𝑟
• 5𝑞^2/4𝜋𝜀_o𝑟

A positive charge +𝑄 is located at +2 on the 𝑦 −axis, while a negative charge −4𝑄 is located at +3 on the 𝑥 −axis. Determine which arrow best represents the direction of the electric field at point 𝑃 located at the origin.←

•  
  
  ←
• east of south
• north of east
• north of west