List of practice Questions

Ultimate product is obtained on heating $B_{2} H_{6}$ with $N H_{3}$ is
A given object takes $n$ times more time to slide down a $45^{\circ}$ rough inclined plane as it takes to slide down a perfectly smooth $45^{\circ}$ incline. The coefficient of kinetic friction between the object and the incline is :
A concave mirror of focal length $f$ produces a real image $n$ times the size of the object. The distance of the object from the mirror is
A compound microscope has a magnification of $ 30 $ . The focal length of the eye-piece is $ 5\,cm $ If the final image is formed at the least distance of distinct vision $ (25\,\,cm) $ the magnification produced by the objective is
A citizen group called Friends of the Arcata Marsh $(FOAM)$ basically belongs to
Three boys and two girls stand in a queue. The probability that the number of boys a head of every girl is atleast one more that the number of girls ahead of her, is
In the quadratic equation $p(x) = 0$ with real coefficients has purely imaginary roots. Then, the equation $p[p(x)] = 0 $ has
The locus of the foot of perpendicular drawn from the centre of the ellipse $ x^2 + 3y^2 = 6$ on any tangent to it is
From a point $P (\lambda, \lambda, \lambda)$, perpendiculars $PQ$ and $PR$ are drawn respectively on the lines $y=x, z=1$ and $y=$ $-x, z=-1$. If $P$ is such that $\angle QPR$ is a right angle, then the possible value(s) of $\lambda$ is(are)
Let $M$ and $N$ be two $3 \times 3$ matrices such that $MN = NM$. Further, if $M \neq N ^{2}$ and $M ^{2}= N ^{4}$, then
A beam of parallel light rays is incident on a solid transparent sphere of refractive index $ \mu $ . If a point image is produced just at the back of the sphere, what is the refractive index of the sphere?
Four conductors carrying $2.0\, A$ of current into or out of the page are shown in the diagram. $A$ path $C$ is indicated for the line integral $\oint B$. $d s$. Find the value of the integral for the path $C$.
In a container, $200 \,g$ of aluminum (specific heat $900\, J / kg K$ ) at $100^{\circ} C$ is mixed with $50\, g$ of water at $20^{\circ} C$, with the mixture thermally isolated. Find the entropy change of the aluminumwater system.
A $70 \,cm$ long sonometer wire is in unison with a tuning fork. If the length of the wire is decreased by $1.0\, cm$, it produces $4$ beats per second with the same tuning fork. The frequency of the tuning fork is
A straight wire of mass $300 \,g$ and length $ 2.5\,m $ carries a current of $ 3.5\,A $ . It is suspended in mid-air by a uniform horizontal magnetic field $B$. What is the magnitude of the magnetic field?
A solenoid of length $0.6 \,m$ has a radius of $1 \,cm$ and is made up of $600$ turns. It carries a current of $6 \,A$. What is the magnitude of the magnetic field inside the solenoid?
The bus moving with a speed of $42 \,km / h$ is brought to a stop by brakes after $6\, m$. If the same bus is moving at a speed of $90 \,km / h$, then the minimum stopping distance is
The Lenz's law is the consequence of the conservation of
The waves used for line-of-sight $(LOS)$ communication is
Which of the following processes will be most adversely affected if microorganisms are removed from a forest ecosystem?
Residual, persistent nucellus present in some seeds is known as
Which pair of plants placed in the family- Solanaceae?
$PAE$ stands for
Yeast is used for commercial production of
Microbe used as clot buster during myocardial infraction