List of practice Questions

A convex lens of focal length 20 cm placed in contact with a plane mirror acts as a
A convex lens of focal length 25 cm is placed at a distance x from a concave lens of focal length 7 cm. When a parallel beam is incident on the convex lens, it emerges as a parallel beam out of the concave lens. The value of x is
A convergent beam of light passes through a diverging lens of focal length $0.2\, m$ and comes to focus $0.3\, m$ behind the lens. The position of the point at which the beam would converge in the absence of the lens is
A national level approach to build up a reproductively healthy society was taken up in our country in
Amniocentesis involves the analysis of
The correct surgical procedure as a contraceptive method is
A constant torque of $31.4\, Nm$ is exerted on a pivoted wheel. If angular acceleration of wheel is $4\pi\,rad\,s^{-2}$, then the moment of inertia of w heel is
A conjoint and open vascular bundle will be observed in the transverse section of
A constant force acting on a body of mass of $5 \,kg$ change its speed from $5\, m s^{-1}$ to $10\, ms^{-1}$ in $10\, s$ without changing the direction of motion. The force acting on the body is
A constant retarding force of $50 \,N$ is applied to a body of mass $10\, kg$ moving initially with a speed of $10\, m\, s^{-1}.$ The body comes to rest after
A conducting metal circular-wire-loop of radius $r$ is placed perpendicular to a magnetic field which varies with time as $B=B_{0}e^{\frac{t}{\tau}}$, where $B_{0}$ and $\tau$ are constants, at time $t = 0$. If the resistance of the loop is $R $ then the heat generated in the loop after a long time $(t \rightarrow\infty)$ is
A conducting loop carrying a current $I$ is placed in xy plane . A uniform magnetic field pointing into Z direction is switched on. The loop will have a tendency to
In Young's double slit experiment, the distance between two sources is $0.1 \,mm$. The distance of the screen from the source is $20\, cm$. Wavelength of light used is $5460\, ?$. The angular position of the first dark fringe is
A conducting circular loop is placed in a uniform magnetic field, $B = 0.025\, T$ with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of $1 \,mm \,s^{-1}$. The induced emf when the radius is $2 \,cm$, is
Bakelite is obtained from phenol by reacting with
A concave shaving mirror has a radius of curvature of $35.0 \,cm$. It is positioned so that the (upright) image of a mans face is $2.50$ times the size of the face. How far is the mirror from the face?
Which of the following is not a condensation polymer ?
A compound microscope consists of an objective lens with focal length $1.0 \,cm$ and eye piece of focal length $2.0\, cm$ and a tube length $20 \,cm$ the magnification will be
A compound is formed by two elements $Y$ and $Z$. The element $Z$ forms $ccp$ and atoms $Y$ occupy $1/3\, rd$ of tetrahedral voids. The formula of the compound is
A compound 'A' having the molecular formula $C_5H_{12}O$ on oxidation gives a compound 'B' with molecular formula $C_5H_{10}O$. Compound 'B' gave a 2, 4-DNP derivative but did not give the haloform test. The structure of the compound A is
A compound $(A)$ of molecular formula $C_7H_8O$ is insoluble in water and dilute sodium bicarbonate but dissolves in dilute aqueous sodium hydroxide and gives a characteristic colour with aqueous $FeCl_3$. On treatment with bromine water, it readily gives a precipitate of $C_7H_5OBr_3$. Write down the structure of the compound $(A)$.
A compound is formed by two elements X and Y. Atoms of the element Y (as anions) make ccp and those of the element X (as cations) occupy all the octahedral voids. What is the formula of the compound?
A compound $'A'$ having the molecular formula $C+{5}H_{12}O$, on oxidation gives a compound $'B'$ with molecular formula $C_{5}H_{10}O$. Compound $'B'$ gave a $2,4-$dinitrophenylhydrazine derivative but did not answer haloform test or silver mirror test. The structure of compound $'A'$ is
If the melting point of ice is $0^?C$ and latent heat of fusion is $5.46\, kJ\, mol^{-1}$, the entropy change for the conversion of $18\, g$ of ice to water at one atmosphere is
A complex involving $dsp^2$ hybridisation has