The orbital angular momentum is given by: \[ L = \frac{\sqrt{l(l+1)}h}{2\pi}. \] For an \(s\)-orbital, \(l = 0\). Substituting \(l = 0\): \[ L = \frac{\sqrt{0(0+1)}h}{2\pi} = 0. \]
Final Answer: \( \boxed{0} \).
Regarding the molecular orbital (MO) energy levels for homonuclear diatomic molecules, the INCORRECT statement(s) is (are):

Two circular discs of radius \(10\) cm each are joined at their centres by a rod, as shown in the figure. The length of the rod is \(30\) cm and its mass is \(600\) g. The mass of each disc is also \(600\) g. If the applied torque between the two discs is \(43\times10^{-7}\) dyne·cm, then the angular acceleration of the system about the given axis \(AB\) is ________ rad s\(^{-2}\).
