Class 12th

Nitrogen gas is obtained by thermal decomposition of

Dihydrogen reacts with CuO to give

Given are two statements one is labeled as Assertion A and other is labeled as Reason R.

Assertion A : Magnesium can reduce Al₂O₃ at a temperature below 1350°C, while above 1350°C aluminium can reduce MgO

Reason R : The melting and boiling points of magnesium are lower thatn those of aluminium.

In light of the above statements, choose most appropriate answer for the options given below

Element “E” belongs to the period 4 and group 16of the periodic table. The valence shell electron configuration of the element, which is just above “E” in the group is

The Zeta potential is related to which property of colloids

The incorrect statement about the imperfections in solids is

A small bar magnet placed with its axis at ${30}^{?}$ with an external field of $0.06\mathrm{T}$ experiences a torque of $0.018\mathrm{N}\mathrm{m}$ . The minimum work required to rotate it from its stable to unstable equilibrium position is:

For a transverse wave traveling along a straight line, the distance between two peaks (crests) is 5
 , while the distance between one crest and one trough is 1.5 m. The possible wavelengths (in $\mathrm{A}\to \mathrm{I}\mathrm{V};\mathrm{}\mathrm{B}\to \mathrm{I}$ ) of the waves are:

A air bubble of radius 1 cm in water has an upward acceleration 9.8 cm^-2 . The density of water is 1 gmcm^-3 and water offers negligible drag force on the bubble. The mass of the bubble is: (g=980 cm/s²)

For a transverse wave traveling along a straight line, the distance between two peaks (crests) is 5
 , while the distance between one crest and one trough is 1.5 m. The possible wavelengths (in $\mathrm{A}\to \mathrm{I}\mathrm{V};\mathrm{}\mathrm{B}\to \mathrm{I}$ ) of the waves are: