When a person is suffering from problem in vision met a doctor , he wrote in his prescription the following figures. +1.5D,-2D
Which are the types of lenses prescribed here ?

When a person is suffering from problem in vision met a doctor , he wrote in his prescription the following figures. +1.5D,-2D What has the doctor indicated in the prescription?

a. When energy of eleçtron is to be taken to zero? b. Which of the following orbitals are not possible? Give reasons 3 s, 1 p, 4 f, 2 d

Consider a voltaic cell constructed with the following substances: 'Cr^(3+)(aq)+3 e^- rarr Cr(s) E^circ=-0.74 V' 'MnO_4^-(aq)+8 H^+(aq)+5 e^- rarr Mn^(2+)(aq)+4 H_2 O(l)' 'E^circ=+1 . 5 1 V' a) Which substances are oxidised and reduced in this cell? b) Write the overall cell equation and calculate the cell potential. c) Which are the negative and positive electrodes? d) Write the cell notation for this voltaic cell.

A doctor is to visit a patient. From the past experience, it is known that the probabilities that he will come by train, bus, scooter or by other means of transport are respectively. 3/10, 1/5, 1/10 and 2/5 . The probabilities that he will be late are 1/4, 1/3 , and 1/12 , if he comes by train, bus and scooter respectively, but if he comes by other means of transport, then he will not be late. When he arrives, he is late. What is he probability that he comes by train?