List of practice Questions

The nature of positive rays depends on
One mole of oxygen gas at STP is equal to
Mean distance between atoms in the range of
When boron \(_{5}B^{10}\) is bombarded by neutron, alpha particles are emitted. The resulting nucleus has the mass number.
A piece of an ancient wooden boat shows an activity of C14 of 3.9 disintegrations per minute per gm of carbon. Estimate the age of the boat, if the half life of C14 is 5.568 years. Assume that the activity of fresh carbon -14 is 15.6 dpm.gm
Which of the following transitions in hydrogen atoms emit photons of highest frequency?
The most widely used rectifier is
Connecting a lead from the negative to the positive of a battery will produce
X-rays of wavelength 1.14 A in the first order reflection from a crystal, were reflected at an angle of 30o.
The inter planar distance in the crystal is (Sin 30ois 0.5)
A pair of coil has a mutual inductance of 2 H, if the current in the primary changes from 10 A to zero in 0.1 S, the induced emf in the secondary will be
The unit of relative permittivity is
The frequency of the charged particle circular at right angles to a uniform magnetic field does not depend upon the
The ratio of the radii of the nuclei \(_{13}Al^{27}\) and \(_{52}Te^{125}\) is approximately
If ionising energy of H atom is 13.6eV, then the second ionising energy of He should be
Radiation of two photons having energies twice and five times the work function of a metal are incident successively on the metal surface.Find out the ratio of maximum velocity of photo electrons emitted in the two cases.
An electron in Bohr's hydrogen atom has an energy of -3.4 eV. The angular momentum of the electron is:
Weak nuclear forces act on
If the rate at which the radiation is conuited by a black body at 0oC is 2 watt, the rate of emission at 273oC will be
If the door of a refrigerator in a room is kept open, the temperature of room will be
The resolution limit of eye is 60 s. At a distance of X km from the eye two persons stand with lateral separation of 3 m. For the two persons to be just resolved by eye, X should be
Convex lens always gives a real image if the object is situated beyond ______________
How many orders will be visible if the wavelength of the incident radiation is 5000 and the number of lines on the grating is 2620 in one inch?
Huygen's principle of secondary waves is used to
What determines the charge that flows through a circuit due to the induced emf?
A stone is dropped into a lake by a person from a 500m high tower. He would hear the sound after approximately