The human eye has an approximate angular resolution of $$\theta$$ = 5.8 $$\times$$ 10$$-$$4 rad and typical photo printer prints a minimum of 300 dpi (dots per inch, 1 inch = 2.54 cm). At what minimal distance d should a printed page be held so that one does not see the individual dots?
Suppose in a hypothetical world the angular momentum is quantized to be even integral multiples of $${h \over {2\pi }}$$. The largest possible wavelength emitted by hydrogen atoms in visible range in a world according to Bohr's model will be,
(Consider hc = 1242 Mev-fm)
A Zener diode having break down voltage Vz = 6V is used in a voltage regulator circuit as shown in the figure. The minimum current required to pass through the Zener to act as a voltage regulator is 10 mA and maximum allowed current through Zener is 40 mA. The maximum value of Rs for Zener to act as a voltage regulator is
The expression $$\overline A (A + B) + (B + AA)(A + \overline B )$$ simplifies to