Dual Nature Of Light Question 17
Question: Assertion : In Millikan’s experiment for the determination of charge on an electron, oil drops of any size can be used. Reason : Millikan’s experiment determine the charge on electron, by simply measuring the terminal velocity.
Options:
A) If both assertion and reason are true and the reason is the correct explanation of the assertion.
B) If both assertion and reason are true but reason is not the correct explanation of the assertion.
C) If assertion is true but reason is false.
D) If the assertion and reason both are false.
E) If assertion is false but reason is true.
Show Answer
Answer:
Correct Answer: E
Solution:
In Millikan?s experiment oil drops should be of microscopic sizes. If much bigger oil drops are used, then a very high electric field will be required to balance it which is not possible to achieve practically. Further, the apparent weight of the liquid $ \frac{4}{3}\pi a^{3}g $ $ ({\rho_{liquid}}-{\sigma_{air}})=6\pi a\eta v. $ If a is large, $ v $ will be large and the experimental errors will be high.
BETA
