1
JEE Advanced 2016 Paper 1 Offline
Numerical
+3
-0
A hydrogen atom in its ground state is irradiated by light of wavelength 970$$\mathop A\limits^o$$.

Taking hc = 1.237 $$\times$$ 10$$-$$6 eVm and the ground state energy of hydrogen atom as $$-$$ 13.6 eV, the number of lines present in the emission spectrum is
2
JEE Advanced 2016 Paper 1 Offline
Numerical
+3
-0
The isotope $$_5^{12}B$$ having a mass 12.014 u undergoes $$\beta$$-decay to $$_6^{12}C$$. $$_6^{12}C$$ has an excited state of the nucleus ($$_6^{12}C$$*) at 4.041 MeV above its ground state. If $$_5^{12}B$$ decays to $$_6^{12}C$$*, the maximum kinetic energy of the $$\beta$$-particle in units of MeV is (1u = 931.5 MeV/c2, where c is the speed of light in vacuum).
3
JEE Advanced 2015 Paper 2 Offline
Numerical
+4
-0
For a radioactive material, its activity A and rate of change of its activity R are defined as $$A = - {{dN} \over {dt}}$$ and $$R = - {{dA} \over {dt}}$$, where N(t) is the number of nuclei at time t. Two radioactive source P(mean life $$\tau$$) and Q (mean life 2$$\tau$$) have the same activity at t = 0. Their rate of change of activities at t = 2$$\tau$$ are RP and RQ, respectively. If $${{{R_P}} \over {{R_Q}}} = {n \over e}$$, then the value of n is
4
JEE Advanced 2015 Paper 1 Offline
Numerical
+4
-0
Consider a hydrogen atom with its electron in the nth orbital. An electromagnetic radiation of wavelength 90 nm is used to ionize the atom. If the kinetic energy of the ejected electron is 10.4 eV, then the value of n is (hc = 1242 eV nm)