Consider the following statements: 1. Size of the sun at dusk 2. Colour of the sun at dawn 3. Moon being visible at dawn 4. Twinkle of stars in the sky 5. Polestar being visible in the sky Which of the above are optical illusions?

LASIK (Laser Assisted In Situ Keratomileusis) procedure is being made popular for vision correction. Which one of the following statements in this context is not correct ?

A lens has a power of +2.0 Dioptre. Which one of the following statements about the lens is true ?

Raman effect is due to Sir C. V. Raman. Which of the following statements is correct about 'Raman effect?

Which one of the following statements about the aperture of a convex lens is correct?

In case of a concave mirror, if an object is kept between principal focus F and pole P of the mirror, then which one of the following statements about the image is NOT correct?