Electric Fields & Potential Energy Review

An electron has a charge of magnitude e = 1.6 x 10^-19 C. The electron is fired through a voltage of 1V, converting electric potential energy to kinetic energy. This is an important unit of energy in particle physics called an electron-volt. $1\ eV\ \ =\ \left(1\ e\right)\times\left(1\ volt\right)$  
How much energy is this in joules?

• 1.6 x 10^-19 J

• 6.3 x 10^18 J

• 1 J

• 4 x 10^-10 J

A tiny sphere carrying a charge of 6.5 x 10^-6 C sits in an electric field, at a point where the electric potential is 240 V relative to ground. What is the sphere’s potential energy?

• 2.7 x 10^-8 J

• 6.5 x 10^-6 J

• 1.6 x 10^-3 J

• 240 J

Tags

NGSS.HS-PS3-1

An electron is drifting at a constant speed when it suddenly encounters a uniform electric field at point i. The electron moves from point i to point f, in the same direction that the uniform electric field points. Which of the following statements is true?

• The electric field causes the electron to speed up from point i to point f.

• The electric field causes the electron to slow down from point i to point f

• The electron is going from lower electric potential to higher electric potential

• The electron continues to drift at a constant velocity through the field.

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

If 500 J of energy are required to carry a 40 C charge from one point to another, the potential difference between these two points is:

• 12.5 V

• 20,000 V

• 0.08 V

• depends on how they were moved

The potential difference between two points is 100 V. If a particle with a charge of 2 C is transported from one of these points to the other, the magnitude of the work done is: 

• 200 J
• 100 J
• 50 J
• 2 J

During a lightning discharge, 30 C of charge move through a potential difference of 1.0 x 10⁸ V. The energy released by this lightning bolt is:

• 1.5 ´ 10¹¹ J

• 3.0 ´ 10⁹ J

• 6.0 ´ 10⁷ J

• 3.3 ´ 10⁶ J

Tags

NGSS.HS-PS3-1

A particle with mass m and charge –q is projected with speed v₀ into the region between two parallel plates as shown. The potential difference between the two plates is V and their separation is d. The change in kinetic energy of the particle as it traverses this region is:

• –qV/d
• 2qV/mv²
• qV
• 1/2 mv²

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

This model of the balloon shows ______ positive charges than negative charges. So this balloon is _____ charged.

• fewer/positively

• more/positively

• fewer/negatively

• more/negatively

Tags

NGSS.HS-PS2-4

NGSS.HS-PS3-5

As a proton moves in the direction the electric field lines...

• it is moving from low potential to high potential and gaining electric potential energy.
• it is moving from low potential to high potential and losing electric potential energy.
• it is moving from high potential to low potential and gaining electric potential energy.
• it is moving from high potential to low potential and losing electric potential energy.

Tags

NGSS.HS-PS3-5

NGSS.HS-PS3-2

Q_A and Q_B are two charges creating an electric field. Based on the electric field lines, we can conclude

• Q_A and Q_B are both positive
• Q_A and Q_B are both negative
• Q_A is positive and Q_B is negative
• Q_A is negative and Q_B is positive

Tags

NGSS.HS-PS2-4