NSMQ 2021 past questions with answers

Answer

−30 V

1. 1.Calculate the change in magnetic flux: $\Delta \Phi ={\Phi }_f-{\Phi }_i=5.0\text{Wb}-(-1.0\text{Wb})=6.0\text{Wb}$.
2. 2.Apply Faraday’s law: $\mathcal{E}=-\frac{\Delta \Phi }{\Delta t}=-\frac{6.0\text{Wb}}{0.20\text{s}}=-30\text{V}$.
3. 3.Interpret the negative sign using Lenz’s law: it indicates the direction of the induced emf opposes the increase in flux.

Answer

y = −x + 1

1. 1.Label the points A(3,−2) as $(x_1,y_1)$ and B(1,0) as $(x_2,y_2)$.
2. 2.Compute the slope using $m=\frac{y_2-y_1}{x_2-x_1}=\frac{0-(-2)}{1-3}=\frac{2}{-2}=-1$.
3. 3.Use the point-slope form $y-y_1=m(x-x_1)$ with A to get $y+2=-1(x-3)$, then simplify to $y=-x+1$.

Answer

Volumetric flask.

1. 1.Recall that preparing a solution of accurately known concentration requires measuring an exact volume of liquid.
2. 2.Eliminate beakers and Erlenmeyer flasks due to their low accuracy and graduated cylinders due to multiple calibration marks and higher error.
3. 3.Identify the volumetric flask, which is specifically designed with a single, precise calibration mark for accurate bulk solution preparation.

Answer

0

1. 1.Identify that ozone is a pure elemental form of oxygen (allotrope).
2. 2.Recall the rule that any atom in its elemental (uncombined) state has an oxidation state of 0.
3. 3.Therefore, each oxygen atom in O3 has an oxidation state of 0.

Answer

It moves in the same direction as the incoming object.

1. 1.Initial momentum $p_i=m_1{v}_1=2\times 5=10\mathrm{kg}m/s$ toward the incoming object.
2. 2.After collision the masses stick, total mass $m=2+1=3\mathrm{kg}$ and by conservation $p_i=mv$.
3. 3.Solve $v=p_i/m=10/3\approx 3.33m/s$ which is positive, i.e. in the same direction as the incoming object.

Answer

$\frac{1}{7}$

1. 1.Rewrite 3x−y=5 in the form y=mx+c: 3x−y=5 ⇒ −y=5−3x ⇒ y=3x−5, so m₁=3.
2. 2.Identify slope of y=2x+3 as m₂=2.
3. 3.Apply the angle formula: tanθ=| (m₁−m₂)/(1+m₁m₂) | = | (3−2)/(1+3·2) | =1/7.

Answer

False

Because PH3 and SiH4 are essentially non-acidic while only H2S and HCl exhibit acidity, the blanket claim that all period-3 hydrides (except argon) are acidic is incorrect.

Answer

True

A cube has six faces and thus satisfies the definition of a hexahedron, which is any six-faced polyhedron.

Answer

484

Answer

Bond energy