Quick questions on Millikan's oil drop experiment: HSC Physics Module 8

5short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What are two methods?

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Stationary method (the simplest to describe). Adjust the voltage until a chosen droplet hangs motionless. The electric force on the charge balances gravity:

What is stationary method?

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Adjust the voltage until a chosen droplet hangs motionless. The electric force on the charge balances gravity:

What is q1?

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State Millikan's conclusion about electric charge from the oil-drop experiment. [2 marks]

What is q2?

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An oil drop of mass

3.2 \times 10^{-15} \text{ kg}

is held stationary between parallel plates separated by

1.0 \text{ cm}

with

V = 980 \text{ V}

applied. Calculate the drop's charge and the number of excess electrons. [4 marks]

What is q3?

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Millikan observed drops with the following charges (in units of

10^{-19} \text{ C}

1.6, 3.3, 4.7, 6.5, 8.0

. (a) Identify the common factor. (b) Explain why no drops had charge

2.4 \times 10^{-19} \text{ C}

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