In Millikan oil drop experiment, when the switch is opened and by altering supply the charge of electron is determined.
Millikan's oil drop experiment is held to determine the terminal velocity and charge of the oil drop.
Firstly without any supply of voltage when an oil drop is sprinkled and these droplets gather electrons together and gives negative charge as they pass through air.
By applying and altering voltage applied on the plates, drop can be suspended in air. Millikan observed one drop after another, varying the voltage and noting the effect. After many repetitions he concluded that charge could assume only certain fixed values.
After conducting many times he concluded 1.602176487 ×10−19 C as the charge of an electron.
City A will have a higher temperature overall than City B (D)
If all factors other than elevation are the same for both cities, then City A will have a higher temperature overall than City B. This is because there are fewer air molecules at higher elevations. Fewer air molecules mean less heat is absorbed by the atmosphere, and temperatures are lower. This is why areas high in the mountains are often much cooler than areas down on the plains.
This problem is a very interesting problem. we know wacth:
Speed = distance / time.
Consider that: distance from point A to point B=distance from point B to point A=d
We calculate the time to go from point A to point B. time=distance / speed. T₁=d / (5 m/s)
We calculate the time to go from point B to point A. T₂=d / (2.9 m/s)
Therefore; the total time wil be: T₁+T₂ Total time=d/(5 m/s) + d / (2.9 m/s) Least common multiple=(5 m/s)(2.9 m / s)=14.5 m²/s² Total time=(2.9 m/s d + 5 m/s d)/ 14.5m²/s² Total time=[(7.9 d) m/s] / (14.5 m²/s²) Total time=7.9 d/ (14.5 m/s)
Now, the total distance will be =d+d=2d
Therefore: Average speed=total distance / total time Average speed=[(2d)] / [(7.9 d)/ (14.5 m/s)] Average speed≈3.67 m/s.