Given instructions same as in chapter 1.
Assertion:Ultraviolet radiations are of higher frequency waves are dangerous to human beings.
Reason:Ultraviolet radiations are absorbed by the atmosphere.

Given instructions same as in chapter 1. Assertion:Radio waves can be polarised. Reason:Sound waves in air are longitudinal in nature.

Given instructions same as in chapter 1. Assertion:In Hertz experiment, the electric vector of radiation produced by a source gap is parallel to the gap. Reason:Production of sparks between the detector gap is maximum when it is perpendicular to the source gap.

Given instructions same as in chapter 1. Assertion: For photoelectric effect to take place, the frequency of incident of incident radiations should be more than threshold frequency of a given metal Reason: 1/2 mv^2=h(v-v_0) .

General instructions same as iin chapter 1. Assertion:A bar magnet exerts a torque on itself due to its own field. Reaons: Magnetic field due to a magnet is uniform.

General instructions same as in chapter 1. Assertion:Large angle scattering of alpha particle led to the discovery of atomic nucleus. Reason:Entire positive charge of atom is concentrated in the central core.

General instruction same as in chapter 1. Assertion: Electrons move away from a low potential to high potential region. Reason:Because electrons has negative charge.

Given instructions same as in chapter 1. Assertion: Any substance can be used for the emission of photoelectrons. Reason: Radiations of suitalbe frequency (more than threshold frequency) should be available.

General instructions same as in chapter 1. Assertion:An electron jumps from lower to higher orbit in an atom. Reason:The electron absorbs energy to jump from lower to higher orbit.

Given instructions same as in chapter 1. Assertion: Photoelectric effect demonstrates the particles nature of light. Reason:The number of photoelectrons is proportional to the frequency of light.

General instructions same as in chapter 1. Assertion:A convex mirror cannot form real images. Reason:Convex mirror converges the parallel rays that are incident on it.