NEET UG 2014 — Modern Physics

When the energy of the incident radiation is increased by $20%,$ the kinetic energy of the photoelectrons emitted from a metal surface increased from emitted $0.5 eV$ to $0.8 eV.$ The work function of the metal is:

The barrier potential of a p-n junction depends on: $(a)$ type of semi-conductor material $(b)$ amount of doping $(c)$ temperature Which one of the following is correct?

Hydrogen atom in ground state is excited by a monochromatic radiation of $\lambda =975 Å.$ Number of spectral lines in the resulting spectrum emitted will be:

The given graph represents $V$ - $I$ characteristic for a semiconductor device.  Which of the following statement is correct?

The Binding energy per nucleon of $Li37$ and $He24$ nucleon are $5.60 MeV$ and $7.06 M\mathrm{eV}$, respectively. In the nuclear reaction ${ }_{3}^{7}Li+{ }_{1}^{1}H\rightarrow { }_{2}^{4}He+{ }_{2}^{4}He+Q$, the value of energy $Q$ released is

A radio isotope ‘$X$’ with a half life $1.4\times {10}^{9}$ years decays to ‘$Y$’ which is stable. A sample of the rock from a cave was found to contain ‘$X$’ and ‘$Y$’ in the ratio $1:7$. The age of the rock is

If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de-Broglie wavelength of the particle is: