A person cannot see beyond 2 m. If he has to read a signboard 4 m away, then the power of the lens required is

Power of the Lens if a Person cannot See beyond 2m & has to Read Signboard at 4m

The farthest distance that a person can see clearly is referred to as their far point, and the closest distance that they can see well is referred to as their near point. Many people experience vision issues as they age because of an inherited eye condition. To calculate the power of the lens, Lens formula has to be used which is 1/f = 1/v − 1/u or P = 1/f.

By putting the values in 1/f = 1/v − 1/u, we will get,

1/f = 1/(-2) – 1/(-4)

1/f = 1/(-4)

1/f = −0.25m−1

Therefore, the power of the lens will be -0.25 D.

Summary:

A person cannot see beyond 2 m. If he has to read a signboard 4 m away, then the power of the lens required is

-0.25 D should be the power of the lens if a person cannot see beyond 2 m and he has to read a signboard 4 m away. A lens is a transmissive optical device that concentrates or disperses a light beam through the use of refraction.

Related Questions:

• The escape velocity from the Earth’s surface is v. The escape velocity from the surface of another planet having a radius, four times that of Earth and same mass density is
• If a number ‘x’ is divisible by another number ‘y’, then ‘x’ is also divisible by all the prime factors of ‘y’
• What Steps can be Taken to Control Soil Erosion in the Hilly Areas?
• How Many Terms of the AP : 9, 17, 25, . . . must be taken to Give a Sum of 636?
• Verify that -(-x) = x for (i) x = 11/15 (ii) x = -13/17
• Find Two Numbers whose Sum is 27 and Product is 182
• Find the HCF of 360 and 18144 by Prime Factorization