The electron of hydrogen atom was excited from ground state to a higher orbit. During de-excitation of the electron, photons of six different wavelengths were emitted. If each photon forms a spectral line, how many spectral line will be visible to naked eye?

Anonymous User Chemistry 23 Jun, 2019 1 Answer 86 views



For the estimation of nitrogen, 1.4 g of an organic compound was digested by Kjeldahl method and the evolved ammonia was absorbed in 60 mL of M/10 sulphuric acid. The unreacted acid required 20 mL of M/10 sodium hydroxide for complete neutralization. The percentage of nitrogen in the compound is ?

Rahul Kumar Chemistry 21 Jun, 2019 1 Answer 297 views




A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 10000 V/m, the charge density of the positive plate will be close to

Jitendra Mishra Physics 17 Jun, 2019 1 Answer 72 views







The mi of a rod abt an axis through its axis and perpendicular to it is 1/12ml^2 the rod bent in middle so that 2 halves make angle 60 mi of bent rod abt same axis is

Anonymous User Physics 05 Jun, 2019 0 Answer 67 views


a square is made by joining 4 rods each of mass m and length its mi abt an axis pq in its plane and is passing through 1 of its end

Anonymous User Physics 05 Jun, 2019 1 Answer 78 views











The equilibrium constant of the reaction CH3COOH (l)+C2H5OH (l)=CH3COOC2H5+H2O is 4.if one mole of each of acetic acid and ethyl alcohol are heated in presence of little concentrated H2SO4 at equilibrium the amount of ester present is

Anonymous User Chemistry 28 May, 2019 1 Answer 887 views




 an elemental crystal has a density of 8570kgm3 the packing efficiency is 0.68 if closest distance b/w neighbouring atom is 2.86 angstrom the mass of 1 atom

Anonymous User Chemistry 22 May, 2019 1 Answer 89 views

A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is 45°. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to 30°. Then the speed (in m/s) of the bird is?

Preeti Rai Maths 20 May, 2019 1 Answer 144 views

There is a circular tube in a vertical plane. Two liquids which do not mix and of densities d1 and d2 are filled in the tube. Each liquid subtends 90° angle at centre. Radius joining their interface makes an angle α with vertical. Ratio of d1/d2

Anonymous User Physics 20 May, 2019 1 Answer 221 views



From a tower of height H, a particle is thrown vertically upwards with a speed U. The time taken by the particle, to hit the ground, is n times that taken by it to reach the highest point of its path. The relation between H, u and n is ?

Anonymous User Physics 18 May, 2019 1 Answer 239 views







The radiation corresponding to 3 → 2 transition of hydrogen atom falls on a metal surface to produce photoelectrons. These electrons are made to enter a magnetic field of 3 × 10−4 T. If the radius of the largest circular path followed by these electrons is 10.0 mm, the work function of the metal is close to ?

Anonymous User Physics 12 May, 2019 1 Answer 101 views

A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is 45°. It flies off horizontally straight away from the point O. After one second, the elevation of the bird from O is reduced to 30°. Then the speed (in m/s) of the bird is?

Anonymous User Physics 11 May, 2019 1 Answer 99 views