List of practice Questions

A Point object is moving uniformly towards the pole of a concave mirror of focal length 25 cm along its axis as shown below. The speed of the object is 1 $ms^{-1}$. At t = 0, the distance of the object from the mirror is 50 cm. The average velocity of the image formed by the mirror between time t = 0 and t = 0.25 s is

The brain capacity of Homo habilis

During inelastic collision between two bodies, which of the following quantities always remain conserved?

Ionized hydrogen atoms and $\alpha$-particles with same momenta enters perpendicular to a constant magnetic field. B. The ratio of their radii of their paths $r_H : r_\alpha$ will be :

Body A of mass 4m moving with speed u collides with another body B of mass 2m, at rest. The collision is head on and elastic in nature. After the collision the fraction of energy lost by the colliding body A is :

A force F = 20 + 10y action a particle in y-direction where F is in newton and y in meter. Work done by this force to move the particle from y = 0 to y = 1 m is :

When an unpolarised beam of light of intensity $I_0$ is incident on a polaroid, the intensity of transmitted light is

?Lumen? is the unit of

Two beams of red and violet colour are made to pass separately through a prism with angle of prism $60^{\circ}$. In the position of minimum deviation, the angle of refraction will be:

The molecules of which of the following gases has the highest speed?

Which of the following oxides would be reduced by C? ${Al_2 O_3, MgO, ZnO , CaO, Fe_2 O_3 , PbO} $

Let P be a $2 \times 2$ matrix such that [1 0] P = $ - \frac{1}{\sqrt{2}} [ 1 1]$ and $[0 1] P = \frac{1}{\sqrt{2}} [- 1 1]$ . If 0 and I denote the zero and identity matrices of order 2, respectively, then which of the following options is CORRECT ?

Nylon 66 is formed by

In which compound does H show O. N of -1?

A group 13 element 'X' reacts with chlorine gas to produce a compound $XCl _{3} . XCl _{3}$ is electron deficient and easily reacts with $NH _{3}$ to form $Cl _{3} X \leftarrow NH _{3}$ adduct; however, $XCl _{3}$ does not dimerise. $X$ is

If the length of the latus rectum of an ellipse is $4$ units and the distance between a focus and its nearest vertex on the major axis is $\frac{3}{2}$ units, then its eccentricity is :

If the tangent at $(1, 7)$ to the curve $x^2 = y - 6$ touches the circle $x^2 + y^2 + 16x + 12y + c = 0$ then the value of c is:

The major product obtained in the following reaction is
 

Glucose on prolonged heating with $HI$ gives :

In \(XeO_3F_2\), the number of bond pair(s), \(\pi\)-bond(s) and lone pair(s) on \(Xe\) atom respectively are :

Lithium aluminium hydride reacts with silicon tetrachloride to form :

When metal ? $M$ ? is treated with $NaOH$, a white gelatinous precipitate ?$X$? is obtained, which is soluble in excess of $NaOH$. Compound ?$X$? when heated strongly gives an oxide which is used in chromatography as an adsorbent. The metal ?$M$? is :

Xenon hexafluoride on partial hydrolysis produces compounds ?X? and ?Y?. Compounds ?X? and ?Y? and the oxidation state of Xe are respectively :

Which of the following statements is false?

The predominant form of histamine present in human blood is $(pK_a$ Histidine $= 6.0)$