Q). The midpoint of a thin lens is called
A) focus
B) optic centre
C) centre of curvature
D) principal centre
Q). The distance between two focal points of a thin lens having focal length f is
A) f
B) f/2
C) 2f
D) infinity
Q). Read the following two statements related to a lens and pick the correct answer:
a. Any ray passing along the principal axis is undeviated
b) A ray passing parallel to the principal axis converges at the focus or appears to diverge from the focus
A) only (a) is true
B) only (b) is true
C) both (a) and (b) are false
D) both (a) and (b) are true
Q). An object is placed between the centre of curvature and focus on the principal axis of a convex lens as shown in the figure below. The image is formed
A) beyond C2
B) beyond C1
C) at C1
D) at infinity
Q). The least distance of distinct vision of normal human eye is about
A) 25 cm
B) 50 cm
C) 5 cm
D) infinity
Q). The innermost colour in the rainbow is
A) red
B) green
C) violet
D) yellow
Q). Which of the following statements is correct?
A) A person with hypermetropia can see nearby objects clearly.
B) A person with myopia can see nearby objects clearly
C) A person with hypermetropia cannot see distant objects clearly.
D) A person with myopia can see distant objects clearly.
Q). Which of the following changes takes place when you walk out of bright sun shine into a poorly lit room?
A) The pupil becomes larger
B) The lens becomes thicker
C) The ciliary muscle relaxes
D) The pupil becomes smaller
Q). The phenomenon due to which white light splits into component colours is called
A) refraction of light
B) scattering of light
C) dispersion of light
D) reflection of light
Q). It the potential difference in a circuit is 240 V and the resistance is 60 Ω, then the current flowing through the circuit is
A) 300 A
B) 180 A
C) 0.25 A
D) 4 A
Good