1. The first excitation energy of hydrogen atom is x eV. Then the ionisation energy of the atom would be (in eV)
a) $\frac{3x}{4}$
b) $\frac{4x}{3}$
c) $\frac{x}{4}$
d) $\frac{x}{3}$

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2. The magnification produced by an astronomical telescope for normal adjustment is 10 and the length of the telescope is 1.1 m. The magnification when the image is formed at least distance of distinct vision (D = 25 cm) is
a) 14
b) 6
c) 16
d) 18

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