Question

Which of the following is a unit for intensity of light?
A. Candle power
B. Lux
C. Both A & B
D. None of the above

Answer 1

Every one of the seven essential base units gave by the International System of Units should be recalled and units of any remaining amounts can be found from these 7 base units. Mole, kelvin, ampere, meter, kilogram, second, and candela are the 7 actual essential units utilized for the measure of substance, temperature, electric flow, length, mass, time and glowing power, separately.

Complete solution:
In photometry, radiant force is a normalized model of the affectability of the natural eye, a proportion of the frequency weighted force transmitted by a light source a specific way for each unit strong point, in view of the glow work. The brilliant force SI unit is the candela (cd), a SI base unit.

The units for light power are moreover:
(I). Candle Power
(ii). Lux

In photometry, iridescent force is characterized as a proportion of intensity, a weighted frequency that is delivered a particular way by a light source dependent on glow. It is a standard model that speaks to the natural eye's affectability to noticeable light. Hefner Kerze and light force are extra units of iridescent power.

Hence, the correct option is (C) .

Note:
The principal light force unit is the candela, ostensibly the light produced by one flame, or all the more exactly, "a source that transmits $540\times 1012Hz$monochromatic radiation and has a brilliant power of $\dfrac{1}{683}$ watt for each steradian toward that path." Luminous power ought not be mistaken for glowing motion, which is another photometric unit, and it is seen as power (ii) (in steradians). Accordingly, the SI unit of glowing transition is lumen.