Answer & explanation
Correct answer: option 3
$ L = \frac{nh}{2\pi}$
$ L_1 = \frac{h}{2\pi}$
$L_2 = \frac{2h}{2\pi}$
$\Rightarrow L_2 = 2L_1$
Correct answer: option 3
$ L = \frac{nh}{2\pi}$
$ L_1 = \frac{h}{2\pi}$
$L_2 = \frac{2h}{2\pi}$
$\Rightarrow L_2 = 2L_1$