NEET Questions

The energy of a photon is given by $E = h

u$, where$h$is Planck's constant and$

u$is the frequency. If a new quantity$X$is defined as$X = \frac{h^2

u^3}{E}$, the dimensions of$X$ are:

A photocell with a work function of 2.5 eV is illuminated by light of wavelength 400 nm. What is the maximum speed of the emitted photoelectrons? (Planck's constant $h = 6.63 imes 10^{-34}$ Js, speed of light $c = 3 imes 10^8$ m/s, mass of electron $m_e = 9.11 imes 10^{-31}$ kg)

What is the energy of a photon with a wavelength of $500$ nm?

A broken ligament is being ‘welded’ back in place using 20 ms pulses from a 0.5 W laser operating at a wavelength of 632 nm. The number of photons in 5 pulses of laser are

Monochromatic light of wavelength 667 nm is produced by a helium neon laser. The power emitted is 9 mW. The number of photons arriving per second on the average at a target irradiated by this beam is

Photons emitted in transition of electrons from n = 2 to n = 1 in hydrogen atom is made to fall on a metal surface with work function 1.2 eV. The maximum velocity of photoelectron emitted is nearly equal to

The work function of a metal is ${W_0}$ and $\lambda$ is wavelength of incident radiation. There is no emission of photoelectron when

When ultraviolet radiation is incident on a surface, no photoelectrons are emitted. If a second beam causes photoelectrons to be ejected, it may consist of

Hydrogen atom emits blue light when it changes from $n = 4$ energy level to the $n = 2$ level. Which colour of light would the atom emit when it changes from the $n = 5$ level to the $n = 2$ level

Hydrogen atom emits blue light when it changes from $n = 4$ energy level to the $n = 2$ level. Which colour of light would the atom emit when it changes from the $n = 5$ level to the $n = 2$ level