The magnifying power of a telescope with tube 60 cm is 5. What is the focal length of its eye piece ?

The dimension of stopping potential V₀ in photoelectric effect in units of Planck's constant 'h', speed of light 'c' and Gravitational constant 'G' and ampere A is :

A thermodynamic cycle xyzx is shown on a V-T diagram. The P-V diagram that best describes this cycle is :
(Diagrams are schematic and not to scale)