The work functions of Cesium and Platinum are 1.9 eV and 5.7 eV, respectively. The ratio of their threshold wavelengths, respectively is

A lens is formed by placing the plane faces of two identical plano-convex lenses (each of focal length 40 cm) touching each other. It is used to obtain a real, inverted image of the same size as the object. The distance of the object from the lens is:

A small telescope has an objective lens of focal length 120 cm and an eyepiece of focal length of 5.0 cm. The magnifying power of telescope for viewing distant objects in normal adjustment is

In an inductive circuit, the current falls from 7.5 A to 1.5 A in 0.15 s. It induces emf of 220 V in the inductive coil. The inductance of the circuit is

A rod of 20 cm lying along the horizontal East-West direction falls freely from the roof of a building of height 3 m. If the horizontal component of the Earth's magnetic field is 0.36 G over the region, find the magnitude of Induced emf when it reaches the bottom of the building (take \( g = 10 \text{ m/s}^2 \) at that place)

For which of the following, a capacitor acts as an infinite resistance component in the circuit?

An equiconvex lens has a focal length\(\frac{2}{3}\) times the radius of curvature of either surface. The refractive index of the material of the lens is :

The degradation of humus by microbes to release inorganic nutrients is known as-

The C-O-H bond angle in alcohols is slightly less than tetrahedral angle \(109^{\circ} 28^{\prime}\) due to:

Read the passage carefully and answer the Questions
Werner in 1898, propounded his theory of coordination compounds. In coordination compounds metals show two types of linkages (valences)-primary and secondary. The primary valences are normally ionisable and are satisfied by negative ions. The secondary valences are non-ionisable. These are satisfied by neutral molecules or negative ions. The secondary valence is equal to the coordination number and is fixed for a metal. The ions or group bound by the secondary linkages to the metal have characteristic spatial arrangements corresponding to the different coordination numbers. Both double salts as well as complexes are formed by the combination of two or more stable compounds in stoichiometric ratio. However, they differ in the fact that double salts such as carnallite, Mohr's salt, potash alum etc. dissociate into simple ions completely when dissolved in water. But complex ions do not dissociate completely into simple ions.
Identify the correct formula of Mohr's salt and potash alum, respectively.

The common name of the following compound is

For a maximizing LPP, the constraints are:

The area of the region bounded by the parabola \(y^2=x\) and the straight line 2y = x is