Home
Class 11
PHYSICS
Find the dimensions of Planck's constant...

Find the dimensions of Planck's constant h from the equatioin `E=hv` where E is the energy and v is the frequency.

Text Solution

Verified by Experts

The correct Answer is:
A, B
`E=hv
where E = energy and v = Frequency h= E/v = ([ML^2 T^-2])/([T^-1]) = [ML^2 T^-1]`
Promotional Banner

Similar Questions

Explore conceptually related problems

If the energy, E = G^p h^q c^r, where G is the universal gravitational constant, h is the Planck's constant and c is the velocity of light, then the values of p are q and r are, respectively

A mercury lamp is a convenient source for studying frequency dependence of photoelectric emission, since it gives a number of spectral lines ranging from the Uv to the red end of the visible spectrum. In our experiment with rubidium photo-cell, the following lines from a mercury source were used: lambda_(1) = 3650 Å, lambda_(2) = 4047 Å, lambda_(3) = 4358 Å, lambda_(4) = 5461 Å, lambda_(5) = 6907 Å , The stopping voltages, respectively, were measured to be: V_(01) = 1.28 V, V_(02) = 0.95 V, V_(03) = 0.74 V, V_(04) = 0.16 V, V_(05) = 0 V Determine the value of Planck’s constant h, the threshold frequency and work function for the material. [Note: You will notice that to get h from the data, you will need to know e (which you can take to be 1.6 xx 10^(-19) C ). Experiments of this kind on Na, Li, K, etc. were performed by Millikan, who, using his own value of e (from the oil-drop experiment) confirmed Einstein’s photoelectric equation and at the same time gave an independent estimate of the value of h.]

In problems involving electromagenetism it is often convenlent and informative to express answers in terms of a constant, alpha , which is a combination of the Coulomb constant, k_(e) = 1//4piepsi_(0) , the charge of the electron, e, and h = h//2 , h being Planck's constant. For instant, the lowest energy that a hydrogen atom can have is given by E = 1//2 alpha^(2) mc^(2) , wherer m is the mass of the electron and c is the speed of light. Which of the following is the correct expression for alpha ? (HINt : non-relativistic kinetic energy is 1//2 mv^(2) , where v is speed.)

If the velocity of light c, gravitational constant G and Planck's constant h be taken as fundamental units the dimension of mass in the new system will be-

If the energy of an electron in the second Bohr orbit of H-atom is -E, what is the energy of the electron in the Bohr’s first orbit?

A projectile is fired vertically upwards from the surface of the earth with a velocity Kv_(e) , where v_(e) is the escape velocity and Klt1 .If R is the radius of the earth, the maximum height to which it will rise measured from the centre of the earth will be (neglect air resistance)

Photon is quantum of radiation with energy E = hv, where v is frequency and his Planck's constant. The dimensions of h are the same as that of

In the formula P=(nRT)/(V-b)e^(-a/(RTV)) . Find the dimensions of a and b where P= pressure, n= number of moles. T= temperature, V= volume and R= universal gas constant.

(i) In the explanation of photoelectric effect we assume one photon of frequency with v collides with an electron and transfers its energy.This lead to the equation for the maximum energy E_(max) of the emitted electron as E_(max)=hv-phi_(0) Where phi_(0) is the work function of the metal If an electron absorbs 2 photon (each of frequency v)What will be the maximum energy for the emitted electron? (ii)Why is this fact (two photon absorption)not taken into consueration in our discussion of the stopping potential?