If λ₁ and λ₂ are the wavelengths of the first members of the Lyman and Paschen series respectively, then the λ₁ : λ₂ is
Options
(a) (1:3) (b) (1:30) (c) (7:50) (d) (7:108)
Two nuclei have their mass numbers into the ratio of 1:3. The ratio of their nucleus densities would be
Options
(a) 1 : 3 (b) 3 : 1 (c) (3)¹/³ : 1 (d) […]
If M (A; Z), Mₚ and Mₙ denote the masses of the nucleus AZ X, proton and neutron respectively in units of u (1u = 931.5 MeV/c) and BE represents its bonding energy in MeV, […]
If the nucleus ²⁷₁₃Al has nuclear radius of about 3.6 fm, then ¹²⁵₃₂Te would have its radius approximately as
Options
(a) 9.6 fm (b) 12.0 fm (c) 4.8 fm (d) 6.0 fm
Correct Answer: […]
Fission of nuclei is possible because the binding energy per nucleon in them
Options
(a) increases with mass number at low mass numbers (b) decreases with mass number at low mass numbers (c) […]
In the reaction ₁²H+₁³H+₂⁴He+₀¹n, if the binding energies of ₁²H,₁³H and ₂⁴He are respectively a,b and c (in MeV), then the energy (in MeV) released in this reaction is
Options
(a) a+b+c (b) […]
The Bohr model of atoms
Options
(a) Assumes that the angular momentum of electrons is quantized (b) Uses Einstein’s photoelectric equation (c) Predicts emission spectra for continuous atoms (d) Predicts the same emission […]
If in a nuclear fusion process, the masses of the fusing nuclei be m₁ and m₂ and the mass of the resultant nucleus be m₃, then
Options
(a) m₃=m₁+m₂ (b) m₃=(m₁-m₂) (c) m₃<(m₁+m₂) (d) […]
Complete the reaction: ₀n¹+ ₉₂U²³⁵→₅₆Ba¹⁴⁴+……..+3n
Options
(a) ₃₆Kr⁸⁹ (b) ₃₆Kr⁹⁰ (c) ₃₆Kr⁹³ (d) ₃₆Kr⁹²
Correct Answer:
₃₆Kr⁸⁹
Explanation:
A’ of product of be formed = (235 + 1) – (144 +3) = 236 – […]
If the ionisation energy for the hydrogen atom is 13.6 eV, the energy required to excite it from the ground state to the next higher state is nearly
Options
(a) 3.4 eV (b) […]
2017 Copyright Doctor Dreams Training Academy