Question 11 MarkThe twinkling of a star is due to atmospheric refraction of starlight.AnswertrueView full question & answer→
Question 21 MarkThe absolute refractive index of any medium is greater than 1.AnswertrueView full question & answer→
Question 31 MarkOptician has prescribed corrective lens indicating $-0.4 \text {D}.$ This means the lens prescribed is convex.AnswerfalseView full question & answer→
Question 41 MarkA lens has power $P=5 D$. So, its focal length is $f=0.2 cm$.AnswerfalseView full question & answer→
Question 51 MarkFor a mirror, $m=\frac{v}{u}$ and for a lens $m=-\frac{v}{u}$AnswerfalseView full question & answer→
Question 61 MarkAccording to the New Cartesian sign convention for every mirror and lens, Object distance is taken as negative.AnswertrueView full question & answer→
Question 71 MarkThe central part of a thin lens made of glass works as a rectangular glass slab.AnswertrueView full question & answer→
Question 81 MarkWhen a ray of light enters from an optically denser medium to an optically rarer medium, its speed decreases.AnswerfalseView full question & answer→
Question 101 MarkIf an object is kept at infinite distance from concave mirror, the image is formed at the centre of curvature of the mirror.AnswerfalseView full question & answer→
Question 111 MarkAt least, four rays are required to obtain the position of an image formed by a mirror.AnswerfalseView full question & answer→
Question 121 MarkThe diameter of the reflecting surface of a spherical mirror is known as the aperture of the mirror.AnswertrueView full question & answer→
Question 131 MarkLaws of reflection are not applicable to a rough and irregular surface.AnswerfalseView full question & answer→
Question 141 MarkLaws of reflection are applicable to any type of mirror.AnswertrueView full question & answer→
Question 151 MarkIn case of irregular reflection, the beam of reflected light remains parallel in a specific direction.AnswerfalseView full question & answer→