List of practice Questions

Two charges $4q$ and $q$ are placed $3x$ apart in air $A$ charge $Q$ is placed at a point on the line joining so that the systein of these charges remains in equilibrium. Then, the distance of $Q$ from $4q$ and the value of $Q$ are
The specific heat capacity of a metal at low temperature (T) is given as : $C_{p} \left(kjK^{-1} kg^{-1}\right) = 32 \left(\frac{T}{400}\right)^{3}$ A 100 gram vessel of this metal is to be cooled from $20^{\circ}K$ to $4^{\circ}K$ by a special refrigerator operating at room temperature $\left(27^{\circ}C\right)$. The amount of work required to cool the vessel is :
Total number of solutions of $ sin^4x +cos^4x = sin x cos x $ is $ [0,2\pi] $ is equal to
A solution is $0.1 M$ with respect to $Ag ^{+}, Ca ^{2+}, Mg ^{2+}$ and $Al ^{3+}$, which will precipitate at lowest concentration of $\left[ PO _{4}^{3-}\right]$ when solution of $Na _{3} PO _{4}$ is added?
An unpolarized light is incident on a system of two crossed polaroids $A$ and $B$. Now the second polaroid $B$ is rotated by, $30^{\circ} $ towards $A$. Percentage of light transmitted through the system is
An aluminium sphere of 20 cm diameter is heated from 0$^{\circ}$C to 100$^{\circ}$C. Its volume changes by (given that coefficient of linear expansion for aluminium $\alpha_{AI} = 23 ? 10^{-6}/^{\circ}C)$
A thin circular disk of radius $R$ is uniformly charged with density $\sigma$ > 0 per unit area. The disk rotates about its axis with a uniform angular speed $\omega$. The magnetic moment of the disk is :
The locus of the point of intersection of the tangents at the extremeties of a chord of the circle $ x^2+y^2 = a^2 $ which touches the circle $ x^2 + y^2 - 2ax = 0 $ passes through the point
The masses of the three wires of copper are in the ratio 5 : 3 : 1 and their lengths are in the ratio 1 : 3 : 5. The ratio of their electrical resistances is
The projections of a directed lines segment on the coordinate axes are $ 12, 4, 3 $ . The direction cosines of the line are
If a spring of stiffness $'k'$ is cut into two parts $'A'$ and $'B'$ of length $\ell_A : \ell_B = 2 : 3$, then the stiffness of spring $'A'$ is given by :
The non aromatic compound among the following is :
If a surface has a work function $4.0 \,eV$, what is the maximum velocity of electrons liberated from the surface when it is irradiated with ultraviolet radiation of wavelength $0.2\, \mu m$ ?
Galileo writes that for angles of projection of a projectile at angles $\left(45^{\circ}+\theta\right)$ and $\left(45^{\circ}-\theta\right)$, the horizontal ranges described by the projectile are in the ratio
Heating of $NH _{4} NO _{3}$ gives
The IUPAC name of the compound is
A reactant (A) forms two products : $ {A ->[k_1] B,} $ Activation Energy $Ea_1$ $ {A ->[k_2] C,}$ Activation Energy $Ea_2$ If $Ea_2 = 2 Ea_1$, then $k_1$ and $k_2$ are related as :
In the series $L-C-R$ circuit shown, the impedance is
Iron is extracted by
An intensive property is
India's first national park is
In angiosperms, transport of food and water is more efficient than gymnosperms and pteridophytes. In angiosperms longitudinally arranged sieve elements and vessels with perforated end walls are present.
Sachin and Rahul attempted to solve a quadratic equaiton. Sachin made a mistake in writing down the constant term and ended up in roots (4, 3). Rahul made a mistake in writing down coefficient of x to get roots (3, 2). The correct roots of equation are :
Sweet potato is homologous to
The basic unit of study in Ecology is