Consider the following statements.
1. Fibre optics is based on the principle of total internal reflection.
2. In an optical fibre communication system, power consumption is extremely low
3. Optical fibre communications are free from radio frequency interference.
4. In India, Reliance Group of Industries is engaged in the manufacture of the optical fibre.
Which of these statements are correct?
A. Only 1, 2 and 3
B. Only 1, 2 and 4
C. Only 1, 3 and 4
D. Only 2, 3 and 4
Answer: Option A
Which combination of colour is the most convenient during day and night time?
A. Orange and blue
B. White and black
C. Yellow and blue
D. Red and green
Lenses with two focal lengths are used by persons suffering from . . . . . . . .
A. Myopia and hypermetropia
B. Myopia or hypermetropia
C. Myopia but not hypermetropia
D. Hypermetropia but not myopia
Which one of the following statements regarding lenses is not correct?
A. A convex lens produces both real and virtual images
B. A concave lens produces both real and virtual images
C. A convex lens can produce images equal, greater and smaller than the size of the object
D. A concave lens always produces images smaller than the size of the object
A. Both 1 and 2
B. Only 1
C. Only 2
D. Neither 1 nor 2

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