Recent questions in 2016

The angle of incidence for a ray of light at a refracting surface of a prism is $45^o$. The angle of prism is $60^o$. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are :

asked Aug 21, 2018 by pady_1

1 answer

A particle of mass 10 g moves along a circle of radius 6.4 cm with a constant tangential acceleration. What is the magnitude of this acceleration if the kinetic energy of the particle becomes equal to $8 \times 10^{–4} J$ by the end of the second revolution after the beginning of the motion ?

asked Aug 21, 2018 by pady_1

1 answer

A refrigerator works between $4^oC$ and $30^oC$. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is : (Take 1 cal = 4.2 Joules)

asked Aug 21, 2018 by pady_1

1 answer

When an $\alpha$-particle of mass 'm' moving with velocity 'v' bombards on a heavy nucleus of charge 'Ze', its distance of closest approach from the nucleus depends on m as :

asked Aug 21, 2018 by pady_1

1 answer

An electron of mass m and a photon have same energy E. The ratio of de-Broglie wavelengths associated with them is :

asked Aug 21, 2018 by pady_1

1 answer

An inductor $20 \;mH$, a capacitor $50 \; \mu F$ and a resistor $40\; \Omega$ are connected in series across a source of emf $V = 10 \sin 340t$. The power loss in A.C. circuit is :

asked Aug 21, 2018 by pady_1

1 answer

A uniform rope of length $L$ and mass $m_1$ hangs vertically from a rigid support. A block of mass $m_2$ is attached to the free end of the rope. A transverse pulse of wavelength $\lambda_1$ is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is $\lambda_2$. The ratio $\lambda_2/\lambda_1$ is :

asked Aug 21, 2018 by pady_1

1 answer

A small signal voltage $V(t )= V_0 \sin \omega t$ is applied across an ideal capacitor C :

asked Aug 21, 2018 by pady_1

1 answer

What is the minimum velocity with which a body of mass m must enter a vertical loop of radius R so that it can complete the loop ?

asked Aug 21, 2018 by pady_1

1 answer

A uniform circular disc of radius 50 cm at rest is free to turn about an axis which is perpendicular to its plane and passes through its centre. It is subjected to a torque which produces a constant angular acceleration of $2.0\; rad\; s^{–2}$ . Its net acceleration in $ms^{–2}$ at the end of 2.0 s is approximately :

asked Aug 21, 2018 by pady_1

1 answer

A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is : [Latent heat of ice is $3.4 \times 10^5 \;J/kg$ and $g = 10\; N/kg$]

asked Aug 21, 2018 by pady_1

1 answer

A particle moves so that its position vector is given by $\overrightarrow{r} = \cos \omega t \;\hat{x} + \sin \omega t \;\hat{y}$. Where $\omega$ is a constant. Which of the following is true ?

asked Aug 21, 2018 by pady_1

1 answer

Two identical charged spheres suspended from a common point by two massless strings of length l, are initially at a distance $d\; (d << l)$ apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity v. Then v varies as a function of the distance x between the spheres, as :

asked Aug 21, 2018 by pady_1

2 answers

A disk and a sphere of same radius but different masses roll off on two inclined planes of the same altitude and length. Which one of the two objects gets to the bottom of the plane first ?

asked Aug 21, 2018 by pady_1

1 answer

If the velocity of a particle is v =$At + Bt^2$, where $A$ and $B$ are constants, then the distance travelled by it between 1s and 2s is :

asked Aug 21, 2018 by pady_1

1 answer

Match the corresponding entries of column 1 with column 2. [Where m is the magnification produced by the mirror] :

asked Aug 21, 2018 by pady_1

1 answer

A long straight wire of radius a carries a steady current $I$. The current uniformly distributed over its cross-section. The ratio of the magnetic fields $B$ and $B'$, at radial distance $\frac{a}{2}$ and $2a$ respectively, from the axis of the wire is :

asked Aug 21, 2018 by pady_1

1 answer

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then :

asked Aug 21, 2018 by pady_1

1 answer

A npn transistor is connected to common emitter configuration in a given amplifier. A load resistance of $800 \Omega$ is connected in the collector circuit and the voltage drop across it is $0.8\; V$. If the current amplification factor is $0.96$ and the input resistance of the circuit is $192 \Omega$, the voltage gain and the power gain of the amplifier will respectively be :

asked Aug 21, 2018 by pady_1

2 answers

An astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective, the lenses must be separated by a distance :

asked Aug 21, 2018 by pady_1

1 answer

If the magnitude of sum of two vectors is equal to the magnitude of difference of the two vectors, the angle between these vectors is :

asked Aug 21, 2018 by pady_1

1 answer

Consider the junction diode as ideal. The value of current flowing through AB is :

asked Aug 21, 2018 by pady_1

1 answer

The molecules of a given mass of a gas have r.m.s velocity of $200 \; ms^{-1}$ at $27^oC$ and $1.0 \times 10^5 \; Nm^{-2}$ pressure. When the temperature and pressure of the gas are respectively, $127^oC$ and $ 0.05 \times 10^5 \; Nm^{-2}$, the r.m.s. velocity of its molecules in $ms^{-1}$ is :

asked Aug 21, 2018 by pady_1

1 answer

An air column, closed at one end and open at the other, resonates with a tuning fork when the smallest length of the column is 50 cm. The next larger length of the column resonating with the same tuning fork is :

asked Aug 21, 2018 by pady_1

1 answer

A black body is at a temperature of $5760 \;K$. The energy of radiation emitted by the body at wavelength $250 \;nm$ is $U_1$, at wavelength $500 \;nm$ is $U_2$ and that at $1000\; nm$ is $U_3$. Wien's constant, $b = 2.88 \times 10^6 \;nmK$. Which of the following is correct ?

asked Aug 21, 2018 by pady_1

1 answer

A square loop ABCD carrying a current i is placed near and coplanar with a long straight conductor XY carrying a current I, the net force on the loop will be :

asked Aug 21, 2018 by pady_1

1 answer

In a diffraction pattern due to a single slit of width 'a', the first minimum is observed at an angle $30^o$ when light of wavelength $5000\; Å$ is incident on the slit. The first secondary maximum is observed at an angle of

asked Aug 21, 2018 by pady_1

1 answer

From a disc of radius R and mass M, a circular hole of diameter R, whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis, passing through the centre ?

asked Aug 21, 2018 by pady_1

1 answer

A body of mass $ 1 \;kg$ begins to move under the action of a time dependent force $\overrightarrow{F} = (2 t \hat{i} + 3 t^2 \hat{j}) N$, where $\hat{i}$ and $\hat{j}$ are unit vectors along x and y axis. What power will be developed by the force at the time $t$ ?

asked Aug 21, 2018 by pady_1

1 answer

A siren emitting a sound of frequency $800\; Hz$ moves away from an observer towards a cliff at a speed of $15ms^{–1}$. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is : (Take velocity of sound in air = $330 \; ms^{-1}$

asked Aug 21, 2018 by pady_1

1 answer

The magnetic susceptibility is negative for :

asked Aug 21, 2018 by pady_1

1 answer

A car is negotiating a curved road of radius $R$. The road is banked at an angle $\theta$. The coefficient of friction between the tyres of the car and the road is $\mu_s$ . The maximum safe velocity on this road is :

asked Aug 21, 2018 by pady_1

1 answer

A long solenoid has $1000\; turns$. When a current of $4A$ flows through it, the magnetic flux linked with each turn of the solenoid is $4 \times 10^{–3}\; Wb$. The self-inductance of the solenoid is :

asked Aug 21, 2018 by pady_1

1 answer

The ratio of escape velocity at earth $(v_e)$ to the escape velocity at a planet $(v_p)$ whose radius and mean density are twice as that of earth is :

asked Aug 21, 2018 by pady_1

1 answer

Given the value of Rydberg constant is $10^7 \;m^{-1}$, the wave number of the last line of the Balmer series in hydrogen spectrum will be :

asked Aug 21, 2018 by pady_1

1 answer

The intensity at the maximum in a Young’s double slit experiment is $I_0$. Distance between two slits is $d = 5 \lambda$, where $\lambda$ is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance $D = 10 \;d$ ?

asked Aug 21, 2018 by pady_1

1 answer

Coefficient of linear expansion of brass and steel rods are $\alpha_1$ and $\alpha_2$. Lengths of brass and steel rods are $l_1$ and $l_2$ respectively. If $(l_2 – l_1)$ is maintained same at all temperatures, which one of the following relations holds good ?

asked Aug 21, 2018 by pady_1

1 answer

At what height from the surface of earth the gravitation potential and the value of $g$ are $– 5.4 \times 10^7 \;J \;kg^{–2}$ and $6.0\; ms^{–2}$ respectively ? Take the radius of earth as $6400\; km$ :

asked Aug 21, 2018 by pady_1

1 answer

The charge flowing through a resistance $R$ varies with time $t$ as $Q = at – bt^2$ , where $a$ and $b$ are positive constants, The total heat produced in R is :

asked Aug 21, 2018 by pady_1

1 answer

Out of the following options which one can be used to produce a propagating electromagnetic wave ?

asked Aug 21, 2018 by pady_1

1 answer

Two non-mixing liquids of densities $\rho$ and $n \rho \;(n > 1)$ are put in a container. The height of each liquid is $h$. A solid cylinder of length $L$ and density $d$ is put in this container. The cylinder floats with its axis vertical and length pL $(p < 1)$ in the denser liquid. The density $d$ is equal to :

asked Aug 21, 2018 by pady_1

1 answer

When a metallic surface is illuminated with radiation of wavelength $\lambda$, the stopping potential is $V$. If the same surface is illuminated with radiation of wavelength $2 \lambda$, the stopping potential is $\frac{V}{4}$. The threshold wavelength for the metallic surface is :

asked Aug 21, 2018 by pady_1

1 answer

A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf’s is :

asked Aug 21, 2018 by pady_1

1 answer

To get output 1 for the following circuit, the correct choice for the input is :

asked Aug 21, 2018 by pady_1

1 answer

A capacitor of $2 \mu F$ is charged as shown in the diagram. When the switch $S$ is turned to position $2$, the percentage of its stored energy dissipated is :

asked Aug 21, 2018 by pady_1

1 answer

Pick out the correct statements : (a) Haemophilia is a ***-linked recessive disease. (b) Down's syndrome is due to aneuploidy (c) Phenylketonuria is an autosomal recessive gene disorder. (d) Sickle cell anaemia is an X – linked recessive gene disorder.

asked Aug 21, 2018 by pady_1

2 answers

Asthma may be attributed to :

asked Aug 21, 2018 by pady_1

1 answer

Which of the following features is not present in the Phylum – Arthropoda?

asked Aug 21, 2018 by pady_1

3 answers

A complex of ribosomes attached to a single strand of RNA is known as :

asked Aug 21, 2018 by pady_1

1 answer

One of the major components of cell wall of most fungi is :

asked Aug 21, 2018 by pady_1

1 answer

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