# Q1 State the laws of refraction of light . If the speed of light in vacuum is 3 × 10⁸ m/s , find the speed of light in a medium of absolute refractive index 1.5. Q2 A concave lens has focal length of 20cm . At what distance from the lens should a 5cm tall object be placed so that it forms an image at 15cm from the lens ? Also , calculate the size of the image formed. Q3 What is the relationship between the S.I unit of power of the lens and S.I unit of focal length ? Q4 the absolute refractive index of benzene and kerosene are 1.50 and 1.44 respectively. What is the refractive index of benzene with respect to kerosene. Q5 Define magnification . Explain why magnification is positive for virtual image and negative for real image ?? Q6 Find the position of an object , which when placed in front of a concave mirror of focal length 10cm produces a virtual image , which is twice the size of the object . Last question Q7 For an object placed at a distance of 20cm from the pole of the mirror , an image is formed , 40cm farther from the object on the same side. a)What is the nature of the mirror ? Give reason for your answer. b)Is the image real or virtual ? Give reason for your answer . c)Draw a ray diagram to show the image formed. d)Calculate the focal length of the mirror used. Please answer all the questions . Please. Thank you in advance.

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by Deleted account
you need to write one query - in one questi on of brainly.. writing so many in one question is difficult for the writers and for the moderators... please understand.