Class 12th

Among the sulphates of alkaline earth metals, the solubilities of BeSO₄ and MgSO₄ in water, respectively, are:

Arrange the following solutions in the decreasing order of pOH
(1) 0.01M HCl
(2) 0.01M NaOH
(3) 0.01M CH₃COONa
(4) 0.01M NaCl

The INCORRECT statement is:

Consider the following reactions:
'A' (C₇H₁₄) --(ozonolysis)--> 'B' + 'C'
'B' --(I₂ + NaOH)--> yellow ppt
'C' --(I₂ + NaOH)--> no yellow ppt
'C' --(Ag₂O/Δ)--> silver mirror
'C' --(LiAlH₄)--> 'D' --(Anhydrous ZnCl₂ & Conc. HCl)--> gives white turbidity within 5 minutes
'A' is:

A part of complete circuit is shown in the figure. At some instant, the value of current I is 1 A and it is decreasing at a rate of 10² As⁻¹. The value of the potential difference Vₚ - Vq, (in volts) at that instant, is

Suppose that intensity of a laser is (315/π) W/m². The rms electric field, in units of V/m associated with this source is close to the nearest integer is (ε₀ = 8.86 * 10⁻¹² C²N⁻¹m⁻²; c = 3 * 10⁸ ms⁻¹)

An electron is moving along +x direction with a velocity of 6 * 10? ms?¹. It enters a region of uniform electric field of 300 V/cm pointing along +y direction. The magnitude and direction of the magnetic field set up in this region such that the electron keeps moving along the x direction will be:

Identify the correct output signal Y in the given combination of gates (as shown) for the given inputs A and B.

The angle of elevation of the top of a hill from a point on the horizontal plane passing through the foot of the hill is found to be 45°. After walking a distance of 80 meters towards the top, up a slope inclined at an angle of 30° to the horizontal plane, the angle of elevation of the top of the hill becomes 75°. Then the height of the hill (in metres) is [numerical value].

Let AD and BC be two vertical poles at A and B respectively on a horizontal ground. If AD=8m, BC=11m and AB=10m; then the distance (in meters) of a point M on AB from the point A such that MD²+MC² is minimum is [numerical value].