Question 32
Lenses and Optical InstrumentsWhen a lamp is placed on the axis and at various distances U from a converging lens, real images are formed at various distances V from the lens. Which of the graphs below will be obtained by plotting the values of quantity y (y = 1/V) against another quantity x (x = 1/U)?
- A.A
- B.B
- C.C
- D.D
- E.E
Show the answer and explanation
Answer: D (D)
Explanation
From 1/V = 1/f − 1/U, the graph of 1/V against 1/U is a straight line with slope −1 that cuts both axes at 1/f, which is graph D.