Assertion : There are very small sporadic changes in the speed of… - Vidyadip

MCQ

$Assertion$ : There are very small sporadic changes in the speed of rotation of the earth
$Reason$ : Shifting of large air masses in the earth's atmosphere produce a change in the moment of inertia of the earth causing its speed of rotation to change.

✓
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
B
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.

✓

Answer

Correct option: A.

If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

a
Along with earth, particles of atmosphere also revolves around the axis of rotation. Now due to change in the constitution of atmosphere there is small change in the total moment of inertia of the whole system. Applying conservation of angular momentum

$I\omega = I'\omega '$

If I' changes, there is corresponding change in the angular velocity of the system

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 6. system of particles and rotational motion→6. system of particles and rotational motion — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

The area of a rectangular field (in $m ^{2}$) of length $55.3\,m$ and breadth $25 \;m$ after rounding off the value for correct significant digits is

$Assertion :$ A brass tumbler feels much colder than a wooden tray on a chilly day.

$Reason :$ The thermal conductivity of brass is more than the thermal conductivity of wood.

If the average life of a person is taken as $100 \,s$, the age of the universe on this scale is of the order ...... $s$

The acceleration of $10\, kg$ block when $F = 30\,N$ ........ $m/s^2$

The three water filled tanks shown have the same volume and height. If small identical holes are punched near this bottom, which one will be the first to get empty.

For which of the following does the centre of mass lie outside the body?

Equation of a plane progressive wave is given by $\text{y}=0.6\sin2\pi\Big(\text{t}-\frac{\text{x}}{2}\Big).$ On reflection from a denser medium its amplitude becomes $2/3$ of the amplitude of the incident wave. The equation of the reflected wave is:

The graph below shows the variation of a force $F$ with time $t$ on a body which is moving in a straight line. Dependence of force on time is $F \propto t^{n}$. Initially body is at rest. If the speed of the object is $2 \,m / s$ at $3 \,s$, then the speed at $4 \,s$ will be approximately (in $m / s$ )

This question has Statement $1$ and Statement $2.$ Of the four choices given after the Statements, choose the one that best describes the two Statements.

Statement $1:$ In the resonance tube experiment, if the tuning fork is replaced by another identical turning fork but with its arm having been filled, the length of the air column should be increased to obtain resonance again.

Statement $2:$ On filling the arms, the frequency of a tuning fork increases.

A hollow spherical ball of uniform density rolls up a curved surface with an initial velocity $3\, m / s$ (as shown in figure). Maximum height with respect to the initial position covered by it will be $...........cm$.