A2L Item 120

• Description: Indicate the size of the electric force on a charge.
• Goal: Problem solving with Coulomb's law
• Source: UMPERG-A2LEM4
• Keywords: Electromagnetism, Forces

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The question for students:

What is the size of the electrical force on the charge q shown in the diagram?

1. √2kqQ/(4a²)
2. kqQ/a²
3. √2kqQ/(2a²)
4. kqQ/(2a²)
5. None of the above

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Commentary for teachers:

Answer

(3) It is a common mistake to forget to take the y-component of the force.

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