A zener of breakdown voltage V_z = 8 V and maximum zener current, I_ZM = 10 mA is subjectd to an input voltage V_i = 10 V with series resistance R = 100 $$\Omega$$. In the given circuit R_L represents the variable load resistance. The ratio of maximum and minimum value of R_L is _____________.

In a Young's double slit experiment, an angular width of the fringe is 0.35$$^\circ$$ on a screen placed at 2 m away for particular wavelength of 450 nm. The angular width of the fringe, when whole system is immersed in a medium of refractive index 7/5, is $${1 \over \alpha }$$. The value of $$\alpha$$ is ___________.

In the given circuit, the magnitude of V_L and V_C are twice that of V_R. Given that f = 50 Hz, the inductance of the coil is $${1 \over {K\pi }}$$ mH. The value of K is ____________.

All resistances in figure are 1 $$\Omega$$ each. The value of current 'I' is $${a \over 5}$$ A. The value of a is _________.