MCQ
The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency ' $\mathrm{A}$ ' $\times 10^{12}$ hertz and that has a radiant intensity in that direction of $\frac{1}{{ }^{\prime}}$ watt per steradian. $'A'$ and $'B'$ are respectively
- A$540$ and $\frac{1}{683}$
- ✓$540$ and $683$
- C$450$ and $\frac{1}{683}$
- D$450$ and $683$
