A telescope with objective diameter R is used to observe a distant star emitting light of wavelength 500 nm, at a resolution of 5 × 10^-7 radian. The…

A telescope with objective diameter $\displaystyle R$ is used to observe a distant star emitting light of wavelength $\displaystyle 500$ nm , at a resolution of $\displaystyle 5 \times 10^{-7}$ radian. The value of $\displaystyle R$ is $\displaystyle \_\_\_\_$ cm.