7.2 Electric Potential and Potential Difference

Potential energy per unit charge, voltage between two points, the electron-volt as an energy unit, and getting voltage differences from a known field.

University Physics Volume 2, 7.2 Electric Potential and Potential Difference

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13 exercises

7.2 Exercise 1

How much energy does a 1.5-V AAA battery have that can move 100 C?

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7.2 Exercise 2

How many electrons would go through a 24.0-W lamp each second from a 12-volt car battery?

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7.2 Exercise 3

How would this example change with a positron? A positron is identical to an electron except the charge is positive.

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7.2 Exercise 4

From the examples, how does the energy of a lightning strike vary with the height of the clouds from the ground? Consider the cloud-ground system to be two parallel plates.

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7.2 Exercise 6

What is the strength of the electric field in a region where the electric potential is constant?

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7.2 Exercise 8

Voltage is the common word for potential difference. Which term is more descriptive, voltage or potential difference?

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7.2 Exercise 10

What is the relationship between voltage and energy? More precisely, what is the relationship between potential difference and electric potential energy?

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7.2 Exercise 12

How are units of volts and electron-volts related? How do they differ?

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7.2 Exercise 14

Find the ratio of speeds of an electron and a negative hydrogen ion (one having an extra electron) accelerated through the same voltage, assuming non-relativistic final speeds. Take the mass of the hydrogen ion to be $1.67 \times 10^{−27} \text{kg} .$

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7.2 Exercise 16

Show that units of V/m and N/C for electric field strength are indeed equivalent.

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7.2 Exercise 18

The electric field strength between two parallel conducting plates separated by 4.00 cm is $7.50 \times 10^{4} \text{V}/\text{m}$ . (a) What is the potential difference between the plates? (b) The plate with the lowest potential is taken to be zero volts. What is the potential 1.00 cm from that plate and 3.00 cm from the other?

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7.2 Exercise 20

Two parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the electric field strength between them, if the potential 8.00 cm from the zero volt plate (and 2.00 cm from the other) is 450 V? (b) What is the voltage between the plates?

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7.2 Exercise 22

An electron is to be accelerated in a uniform electric field having a strength of $2.00 \times 10^{6} \text{V}/\text{m} .$ (a) What energy in keV is given to the electron if it is accelerated through 0.400 m? (b) Over what distance would it have to be accelerated to increase its energy by 50.0 GeV?

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