What is luminous flux in LED?

A huge circular arc of length $4.4 \mathrm{ly}$ subtends an angle $4\mathrm{s}$ at the centre of the circle. How long it would take for a body to complete $4$ revolution if its speed is $8 \mathrm{AU}$ per second?
Given : $1 \mathrm{ly}=9.46\times {10}^{15} \mathrm{m}$

$1 \mathrm{AU}=1.5\times {10}^{11} \mathrm{m}$

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

In two different systems of units, acceleration is represented by the same number while velocity is represented by numbers in the ratio $1:3$. The ratios of unit of length and time are, respectively,

Young’s modulus of a material has the same unit as