Why is this fact (two photon absorption) not taken into consideration in our discussion of the stopping potential?

An express train takes 1 hour less than a passenger train to travel 132 km between Mysore and Bangalore (without taking into consideration the time they stop at intermediate stations). If the average speed of the express train is 11 km/hr more than that of the passenger train, find the average speed of the two trains.

The figure shows the stopping potential for the phototelectron versus (1/lambda) graph for two metals A and B, lambda being the wavelength of incident light If the distance between the light source and the surface of metal A is increased, how will the stopping potentail for the electrons emitted from it be affected? justify your answer.

Calculate the height of the potential barrier for a head on collision of two deuterons. (Hint: The height of the potential barrier is given by the Coulomb repulsion between the two deuterons when they just touch each other. Assume that they can be taken as hard spheres of radius 2.0 fm.)

Maximum kinectic energy of an emitted photon by a photo cell is 2eV. What is stopping potential?

Sketch a graphs showing the variation of stopping potential with frequency of incident radiations for two photosensitive materials A and B having threshold frequencies v_0>v_0' respectively? What does the value of the intercept of graph'A' on the potential axis represent?

Sketch a graphs showing the variation of stopping potential with frequency of incident radiations for two photosensitive materials A and B having threshold frequencies v_0>v_0' respectively? Which of the two metals A or B has higher work function?

Sketch a graphs showing the variation of stopping potential with frequency of incident radiations for two photosensitive materials A and B having threshold frequencies v_0>v_0' respectively? What information do you get from the slope of the graphs?

Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work functions W_1 and W_2 (W_1>W_2). On what factors does the slope and intercept of the lines depends.