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)`.

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.

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.

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:Ultraviolet radiations are of higher frequency waves are dangerous to human beings. Reason:Ultraviolet radiations are absorbed by the atmosphere.

For photoelectric effect in a metal, the figure shows the plot of cut off voltage versus frequency of incident radiations. Calculate (a) the threshold frequency (b) the work function for given metal.

General instructions same as in chapter 1. Assertion:Rydberg's constant varies with mass number of a given element. Resaon:The reduced mass of the electron is dependent on a given element.

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.

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.

General instructions same as in chapter 1. Assertion:Corpuscular theory fails in explaning the velocities of light in air and water. Reason:According to corpuscular theory, light should travel faster in denser medium than in rarer medium.