MCQ
Which of the following quantities is dimensionless
  • A
    Gravitational constant
  • B
    Planck's constant
  • C
    Power of a convex lens
  • None

Answer

Correct option: D.
None
d
$[G] = [{M^{ - 1}}{L^3}{T^{ - 2}}];\,[h] = [M{L^2}{T^{ - 1}}]$

Power = $\frac{1}{{{\rm{focal length}}}} = [{L^{ - 1}}]$

All quantities have dimensions

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

Similar questions

A vibrating string of certain length $\ell$ under a tension $\mathrm{T}$ resonates with a mode corresponding to the first overtone (third harmonic) of an air column of length $75 \mathrm{~cm}$ inside a tube closed at one end. The string also generates $4$ beats per second when excited along with a tuning fork of frequency $\mathrm{n}$. Now when the tension of the string is slightly increased the number of beats reduces $2$ per second. Assuming the velocity of sound in air to be $340 \mathrm{~m} / \mathrm{s}$, the frequency $\mathrm{n}$ of the tuning fork in $\mathrm{Hz}$ is
If C represents capacitance and R represents resistance, then the unit of CR2 are:
The specific heat of a gas
The acceleration of the $2\,kg$ block if the free end of string is pulled with a force of $20\,N$ as shown is
$Assertion :$ The heat supplied to a system is always equal to the increase in its internal energy.
$Reason :$ When a system changes from one thermal equilibrium to another, some heat is absorbed by it.
Two seconds after projection a projectile is travelling in a direction inclined at $30^o$ to  horizontal, after one more second it is travelling horizontally. What is the magnitude and  direction of its velocity at initial point
The spool shown in figure is placed on rough horizontal surface and has inner radius $r$ and outer radius $R$. The angle $\theta$ between the applied force and the horizontal can be varied. The critical angle $(\theta )$ for which the spool does not roll and remains stationary is given by 
A body of mass $m$ hangs at one end of a string of length l, the other end of which is fixed. It is given a horizontal velocity so that the string would just reach where it makes an angle of ${60^°}$ with the vertical. The tension in the string at mean position is
If you set up the seventh harmonic on a string fixed at both ends, how many nodes and antinodes are set up in it
Potential energy of a satellite having mass $‘m’$ and rotating at a height of $6.4 \times {10^6}\,m$ from the earth surface is