Physics-(general)

NEET Physics (general) MCQ Question

Type: MCQ-conceptual-Medium-Class 11

Which of the following statements about the SI unit of luminous intensity, the candela, is correct?

A

The candela is defined using the luminous efficacy of radiation at 540 x 10^12 Hz.

B

The candela is a measure of the total energy emitted by a light source.

C

The SI unit of luminous intensity is based solely on the mass of a body.

D

The candela is equivalent to lumens per watt in all contexts.

Correct Answer

Option A

Detailed Explanation

The candela is indeed defined by taking the fixed numerical value of the luminous efficacy of monochromatic radiation of frequency 540 x 10^12 Hz, which is stated in the NCERT context.

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