MCQ
When a ceiling fan is switched on, it makes $10$ rotations in first $3\,seconds,$ How many rotations will it make in the next $3\,seconds.$ (Assume uniform angular acceleration)
- A$10$
- B$20$
- ✓$30$
- D$40$
✓
Answer
Correct option: C.
$30$
c
For constant acceleration
For constant acceleration
$n_1 : n_2 : n_3 ..... = 1 : 3 : 5 : \,...........$
$\therefore $ if $n_1 = 10$ rotation then $n_2 = 30$ rotation
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
If $a$ person sitting on $a$ rotating stool with his hands outstretched, suddenly lowers his hands, then his
→During an adiabatic process, the pressure of a gas is proportional to the cube of its absolute temperature. The value of $\frac{\text{C}_{\text{p}}}{\text{C}_\text{v}}$ for that gas is:
→A body lying initially at point $(3,7)$ starts moving with a constant acceleration of $4 \hat{i}$. Its position after $3 \,s$ is given by the co-ordinates ..........
→A rod of mass $M$ and length $L$ is placed in a horizontal plane with one end hinged about the vertical axis. A horizontal force of $F=\frac {Mg}{2}$ applied at a distance $\frac {5L}{6}$ from the hinged end. The angular acceleration of the rod will be
→A closed vessel is half filled with water. There is a hole near the top of the vessel and air is pumped out from this hole.
- The water level will rise up in the vessel.
- The pressure at the surface of the water will decrease.
- The force by the water on the bottom of the vessel will decrease.
- The density of the liquid will decrease.
A particle $A$ is projected vertically upwards. Another identical particle $B$ is projected at an angle of $45^o $ . Both reach the same height. The ratio of the initial kinetic energy of $A$ to that of $B$ is
→Identify the correct statement
A cylinder of radius $4\ cm$ and height $10\ cm$ is immersed in two liquids as shown. Specific gravity of oil is $0.5$ . $2\ cm$ of cylinder is in the air. Select the $INCORRECT$ statement. Neglect atmospheric pressure.
→When a car at high speed makes a sharp turn, the driver in the car tends to get thrown in the direction opposite to that of the turn. This is due to which property?
The maximum acceleration of a particle in $SHM$ is made two times keeping the maximum speed to be constant. It is possible when
→