Class 12th

The decreasing order of reactivity of the following organic molecules towards AgNO3 solution is:
(A) Cl
(B) Cl OMe
(C) CH3CHCH3 Cl
(D) CH3CHCH2NO2 Cl

A beam of plane polarized light of large cross-sectional area and uniform intensity of 3.3Wm⁻² falls normally on a polarizer (cross sectional area 3 * 10⁻⁴ m² ) which rotates about its axis with an angular speed of 31.4rad/s. The energy of light passing through the polariser per revolution, is close to:

Take the breakdown voltage of the zener diode used in the given circuit as 6 V. For the input voltage shown in figure below, the time variation of the output voltage is: (Graphs drawn are schematic and not to scale)

Among statements (a) - (d), the correct ones are:

(a) Lime stone is decomposed to  during the extraction of iron from its oxides.

(b) In the extraction of silver, silver is extracted as an anionic complex.

(c) Nickel is purified by Mond's process.

(d) Zr and Ti are purified by Van Arkel method.

A wire A, bent in the shape of an arc of a circle, carrying a current of 2 A and having radius 2 cm and another wire B, also bent in the shape of arc of a circle, carrying a current of 3 A and having radius of 4 cm, are placed as shown in the figure. The ratio of the magnetic fields due to the wires A and B at the common centre O is:

Particle A of mass mₐ = m/3 moving along the x-axis with velocity v₀ collides elastically with another particle B at rest having mass mₑ = m/3. If both particles move along the x axis after the collision, the change ∆λ in de-Broglie wavelength of particle A, in terms of its de-Broglie wavelength (λ₀) before collision is:

Given figure shows few data points in a photo electric effect experiment for a certain metal. The minimum energy for ejection of electron from its surface is: (Plancks constant h = 6.62 * 10?³? J.s )

The total number of structural isomers possible for the substituted benzene derivatives with the molecular formula C?H? is _.