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The rms speed of the molecules of gas A is twice that of gas B. The molecular mass of A is one fourth to that of B.
Answer: Option B
<u>Explanation:</u>
Measuring the speed of particles at a given point in time results in a large distribution of values. Some molecules can move very slowly, others very fast, and because they are still moving in different directions, the speeds may be zero. (Velocity, vector quantity that corresponds to the speed and direction of the molecule.)
To correctly estimate the average velocity, you must take the squares of the mean velocity and take the square root of this value. This is known as the root mean square (rms) velocity and is shown as follows:

Where,
M – Gas’s molar mass
R – Molar mass constant
T – Temperature (in Kelvin)
Given data is rms speed for gas molecule A is twice that of gas molecule B. So,

Therefore, equating the molecule’s rms speed formula for both A and B,

On squaring both sides, we get,

By solving the above equations, we get,

Answer:
The correct answer is: A HARD DISK
Explanation:
Magnetic Disc stores data of different types and formats that can always be edited or erased at any time. An example of a Magnetic Disc is a Hard Disk.
A hard disk is a type of magnetic storage device inside a computer that store data magnetically usually for the long-term and it could store a large volume of data, though that depends on the size, because it comes in various size. However, it generally allows stored data to be retrieved easily.