Question

Q1: Within the experiment you are going to estimate object distance and image distance from object, lens and image positions. Write down the formula you will use to estimate object distance and image distances. object screen lens in holder image screen source optical bench Figure 2 Image fomation by a converging lens Object position, O Lens position, L Image position, I 02: what are the y-axis and x-axis parameters for the graph you will make in this experiment? What does the slope of the graph give you? Q3: In two sentences, explain how it is possible to roughly estimate the focal length of a lens experimentally? Q4: Explain the differences between a real image and a virtual image.

Answer 1

Object distance = distance between lens and object = -[Position of lens - position of objects] + Image distance = d_i = [Position of image - position of lens] Len�s formula rightarrow 1/d_i - 1/d_0 = 1/f rightdoublearrow 1/d_i = 1/d_0 + 1/f so on Y axis we plot 1/d_i and on X axis we plot 1/d_0 the slope of the graph = -1 when 1/d_o = 0 then 1/d_i = 1/f OR d_i = f So the Y intercept = 1/f And from this we can find focal length. Real image rightarrow Image formed, at a point, where light rays really reaches after refraction from lens. Virtual image rightarrow An image, that is appearing but light from object don�t reaches t that point.