JPIHM Meerut Questions and Answers

Dear student,

You are asking if the focal length of a lens is 20 cm, what is its power in diopters?

Calculating Lens Power:

• Power of a lens is defined as the reciprocal of its focal length when expressed in meters
• The unit of power of a lens is diopter (D)

Formula:

• Power (P) = 1 / focal length (in meters)

Given:

• Focal length (f) = 20 cm = 0.2 meters

Calculation:

• Power (P) = 1 / 0.2 = 5 diopters

Therefore, the power of the lens is +5 diopters

Why is it positive?

• A positive power indicates a convex lens (converging lens)
• Convex lenses are thicker at the center and thinner at the edges
• They converge light rays to a point called the focus

convex lens

Additional Notes:

• Concave Lens: If the lens were concave (diverging lens), the power would be negative
• Units: Always ensure that the focal length is converted to meters before calculating the power in diopters

Therefore, if a lens has a focal length of 20 cm, its power is +5 diopters. This means it is a convex lens capable of converging light rays.

Hello Utkarsh,

JP Institute of Hotel Management & Catering Technology located in Meerut, Uttar Pradesh, does not offer M.Tech plus PhD courses. The institute, recognised by the AICTE, New Delhi offers one undergraduate and one diploma-level programme in the field of Hotel Management. JPIHM courses are affiliated to the Dr A.P.J. Abdul Kalam Technical University (AKTU), Uttar Pradesh, Lucknow and the Board of Technical Education (BTE) Uttar Pradesh, Lucknow. The programmes you can opt for here are BHMCT (4 years) and DHMCT (3 years). For admission to the courses offered at JP Institute of Hotel Management & Catering Technology, you must have passed 10+2 in any stream with a minimum of 50% marks in aggregate with English as one of the subjects.

I hope this was helpful. If you require additional information, we will be pleased to assist.