The near point of a patient's eye is 50.0 cm. What po...
The near point of a patient's eye is 50.0 cm. What power (in diopters) must a corrective lens have to enable the eye to see clearly an object 25.0 cm away?
2 diopters
2.5 diopters
0.5 diopters
3 diopters
Correct answer is A
The patient cannot see clearly an object closer than 50 cm
Therefore, the patient needs a lens that would enable him see clearly, objects placed 25 cm from the lens
So, we take the object to a distance of 25 cm from the lens so that the image forms at 50 cm in front of the lens
u=25cm ;v=-50cm (virtual image); p=
1f=1u + 1v
⇒1f =150
⇒1f = 125-150
⇒1f = f = 50cm =0.5m
⇒1f = 2−150
p = 1f
p = 10.5
p = 2 diopters
; The patient needs a converging lens with a power of 2 diopters
Which of the following statements is correct?...
A body of volume 0.046m3 is immersed in a liquid of density 980kgm-3 with 34 of its vol...
The pressure of a gas when cooled at constant volume will decrease because the molecules ...
When electrical power is transmitted over long distances, the voltage is stepped up so that ...
A metal rod has a length of 100cm at 200oC. At what temperature will its length be 99.4cm. If t...
A 10μC charge moves with a velocity of 1.0 x 105 ms-1 at right angle to a uniform magnetic fie...