List of practice Questions

Two spherical black bodies of radii $r_1$ and $r_2$ at temperatures $T_1$ and $T_2$ respectively, radiate same power. Then $\frac{r_1}{ r_2}$ must be equal to
Sulphur dioxide is prepared by the action of
Which one of the following is not affected by concentrated sulphuric acid ?
In a triangle $ABC$ if $\begin{vmatrix}1&a&b\\ 1&c&a\\ 1&b&c\end{vmatrix} = 0$, then $\sin^2 A + \sin^2 B + \sin^2 C = $
A constant force acts on two different masses independently producing accelerations $a_1$ and $a_2$. When the same force acts on their combined mass, the acceleration produced is
Equivalent mass of potassium permanganate in acid medium is
If the area of triangle formed by the points $(\alpha, 0), (0, 1)$ and $(-1, 0)$ is 20 s units, then $\alpha$ is
The magnitude of the magnetic force on a charge is zero when
The area of the triangle whose vertices are $A = (1, -1, 2), B = (2, 1, -1)$ and $C = (3, -1, 2)$ is
The coordinates of the circumcentre of the triangle with vertices $(2, 3), (4, -1) $ and $ (4, 3) $ are
A mixture of aniline and chlorobenzene can, be separated using
The mass of $CaCO_3$ that completely reacts with 1 $dm^3$ of IN hydrochloric acid is
The molecular formula of Ruby silver is
The number of positive divisors of 67375 which are greater than 5 is
If $ \sqrt{x} + \frac{1}{\sqrt{x}} = 2 \, \cos \theta $, then $x^6 + x^6 = $
The differential equation whose general solution is $Ax^2 + By^2 = 1$, where $A$ and $B$ are arbitrary constants is of ?
If $a, b, c$ are in G.P and $x^a = y^b = z^c$, then
The most stable particle in Baryon group is
The increase in pressure required to decrease the 200 L volume of a liquid by 0.004% (in kPa) is (Bulk modulus of the liquid = 2100 MPa)
A light ray in travelling between two media as given below. The angle of incidence on the boundary in all the cases is $30^\circ$. ldentify the correct sequence of increasing order of angles of refraction (1) air to water (2) water to glass (3) glass to water (Refractive indices of glass and water are respectively $\frac{3}{2}$ and $\frac{4}{3}$ )
Four particles, each of mass 1 kg are placed at the comers of a square OABC of side 1 m. O is at the origin of the co-ordinate system. OA and OC are aligned along positive X-axis and positive V-axis respectively. The position vector of the centre of mass is (in m):
In two separate collisions, the coefficients of restitutions $ {{e}_{1}} $ and $ {{e}_{2}} $ are in the ratio 3: 1. In the first collision the relative velocity of approach is twice the relative velocity of separation. Then the ratio between the relative velocity of approach and relative velocity of separation in the second collision is:
Consider the reaction, $N_2(g)+3H_2(g) \to 2NH_3(g)$ The equality relationship between $\frac{d[NH_3]}{dt}$ and $-\frac{d [H_2]}{dt}$ is :-
Two short magnets have equal pole strengths but one is twice as long as the other. The shorter magnet is placed 20 cm in tan A position from the compass needle. The longer magnet must be placed on the other side of the magnetometer for no deflection at a distance equal to
An electric fan has blades of length 30 cm as measured from the axis of rotation. If the fan is rotating at 1200 rpm, the acceleration of a point on the tip of the blade is about