1. The electric field E, current density J and conductivity of a conductor are related as: a) σ = E/J b) σ = J/E c) σ = JE d) σ = 1/JE 2. Two wires each of radius of cross-section r but of different materials are connected together end to end (in series). If the densities of charge carriers in the two wires are in the ratio 1:4, the drift velocity of electrons in the two wires will be in the ratio: b) 1:2 c) 4:1 d) 2:1 e) 1:4 3. A current of 5 A is passing through a metallic wire of cross-sectional area 4 x 10 -6 m 2 . If the density of charge carriers of the wire is 5 x 10 26 m -3 , then the drift velocity of the electrons will be: 1 x...
ATOMS SYLLABUS:(2023-2024) Alpha-particle scattering experiment; Rutherford's model of atom; Bohr model of hydrogen atom, Expression for radius of nth possible orbit, velocity and energy of electron in nth orbit, hydrogen line spectra (qualitative treatment only) 5MARKS 1. (i)With suitable diagram explain the alpha particle experiment and write the observation and conclusion from the graph. (ii)plot the graph number of alpha particle pass through the gold foil vs scattering angle. (iiI)Define impact parameter. Write its significance. 2. Derive the expression for Bohr’s velocity, radius and energy from Bohr’s 2 nd postulate. 3MARKS 1. The total energy of an electron in the first excited state of the hydrogen atom is about –3.4 eV. ...