Explore topic-wise InterviewSolutions in Current Affairs.

Which of the following graphs is the magnification of a real image against the distance from the focus of a concave mirror

A small ball is rolled with speed $u$ from point $A$ along a smooth circular track as shown in figure. If $x=3R$, then determine the point of projection after passing through $C$, the highest point.

A long cylindrical shell carries positive surface charge σ in the upper half and negative surface charge - σ in the lower half. The electric field lines around the cylinder will look like figure given in:

velocity is ω, angular acceleration is α and the torque is τ. Which of the following relations is correct?

An object is displaced from point $A(0,0,0)m$ to a point $B(2,4,6)m$ under the influence of a force $\overrightarrow{F}=2x\hat{i}+3y^2\hat{j}+4z^3\hat{k}.$ The workdone by this force is

A block of mass $2\text{kg}$ initially at rest moves under the influence of a time-dependent force $\overrightarrow{F}=4t\hat{i}.$ The power developed by the force at $t=2\text{seconds}$ is

A listener moves towards stationary sound source with a constant speed and crosses it then the correct graph between Apparent frequency with time is please explain

How many significant figures should be present in the answer of the following calculation?

0.0125+0.7864+0.0215

A horizontal rod of length $l=2\text{m}$ and mass $2\text{kg}$ with the balls $\text{A}$ and $\text{B}$ of mass $1\text{kg}$ each at its ends is clamped at the centre $\text{C}$ in such a way that it can rotate freely about a horizontal axis through the clamp. The system is kept at rest in the horizontal position. A particle $P$ of mass $1\text{kg}$ is dropped from a height of $5\text{m}$ on the ball $B$. The particle collides with $B$ and sticks to it. Find the angular velocity of the system just after the collision.

Uncertainity of the given resistance is

The resultant of two velocity vectors $\overrightarrow{A}$ and $\overrightarrow{B}$ is perpendicular to $\overrightarrow{A}$. The angle between $\overrightarrow{A}$ and $\overrightarrow{B}$ is ${150}^{\circ }$. Find $\frac{|\overrightarrow{R}|}{|\overrightarrow{B}|}$ where $\overrightarrow{R}$ is the resultant vector.

A constant power $P$ is applied to a particle of mass $m$. The distance travelled by the particle when its velocity increases from $v_1\text{to}{v}_2$ is - (neglect friction)

An organ pipe $P_1$ closed at one end vibrating in its first overtone and another pipe $P_2$ open at both ends vibrating in its third overtone are in resonance with a given tuning fork. The ratio of lengths of $P_1$ and P2 is

[EAMCET 1997; MH CET 1999; AFMC 2001]

If velocity of P with respect to Q is 40 km/h, then velocity of Q with respect to P is

A cane filled with water is revolved in a vertical circle of radius 4 meter and the water just does not fall down. The time period of revolution will be

A ball P is dropped vertically and another ball Q is thrown horizontally with the some velocity from the same height and at the same time. If air resistance is neglected, then

A round uniform body of radius R, mass M, and moment of inertia I rolls down (without slipping) an inclined plane making an angle $\theta$ with the horizontal. Then its acceleration is

The saturation current from a thoriated - tungsten cathode at 2000 K is 100 mA. What will be the saturation current for a pure-tungsten cathode of th esame surface area operating at the same temperature ? The constant A in the Rihardson- Dushman equation is $60\times {10}^{4}A{m}^{-2}{K}^{-2}$ for pure tungsten and $3.0\times {10}^{4}A{m}^{-2}{K}^{-2}$ for thoriated tungsten. The work function of pure tungsten is 4.5 eV and that of thoriated tungsten is 2.6 eV.

When forces $F_1,F_2,F_3,$ are acting on a particle of mass m such that $F_{2}and{F}_3,$ are mutually perpendicular, then the particle remains stationary. If the force $F_1$ is now removed then the acceleration of the particle is

A metal piece of mass 160 g lies in equilibrium inside a glass of water. The piece touches the bottom of the glass at a small number of points. If the density of the metal is 8000 kg $m^{-3}$, find the normal force exerted by the bottom of the glass on the metal piece.

If the vectors $3\hat{i}-6\hat{j}+3\hat{k}and2\hat{i}-4\hat{j}+\mu \hat{k}$ are parallel , then α =

Two identical conducting rods are first connected independently to two vessels, one containing water at ${100}^{\circ }$C and the other containing ice at $0^{\circ }$C. In the second case, the rods are joined end to end and connected to the same vessels. Let q1and q2 g / s be the rate of melting of ice in two cases respectively. The ratio of $\frac{q1}{q2}$ is

Axis of a hollow cone shown in figure is vertical. It’s base radius is ‘R’. It is kept in a uniform electric field E parallel to its axis.

The magnitude of flux through curved part of the cone?

Look at the graphs (a) to (d) (Fig. 3.20) carefully and state, with reasons, which of these cannot possibly represent one-dimensional motion of a particle.

a)


b)



c)


d)

White light is used to illuminate the two slits in Young's double slit experiment. The distance between the slits is b and the screen is at a distance d (>> b) from the slits. At a point on the screen directly in front of one of the slits, certain wavelengths are missing. Some of these missing wavelengths are

A particle of mass $100g$ moving at an initial speed $u$ collides with another particle of same mass kept initially at rest. If the total kinetic energy becomes $0.2J$ after the collision, what could be the minimum and the maximum value of $u$?

In the network shown in the figure each of resistance is equal to $2\Omega$. The resistance between A and B is

At a certain instant a stationary transverse wave is found to have maximum kinetic energy. The appearance of string at that instant is

The mathematical form of three travelling waves are given by
$Y_1=\left(2cm\right)sin(3x-6t)Y_2=\left(3cm\right)sin(4x-12t)and{Y}_3=\left(4cm\right)sin(5x-11t)$
of these waves,

A 60 kg body is pushed with just enough force to start it moving across a floor and the same force continues to act afterwards. The coefficient of static friction and sliding friction are 0.5 and 0.4 respectively. The acceleration of the body is

In a coil of resistance $100\Omega$, a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is

Consider the following statements.
If the van der waal's parameter of two gases are given as

$a\left(atm{L}^{2}mo{l}^{-2}\right)b\left(L^{2}mo{l}^{-1}\right)$
Gas X: $6.50056$
Gas Y: $8.00011$

Then $A:V_c\left(X\right)<V_c\left(Y\right)$
$B:p_c\left(X\right)<p_c\left(Y\right)$
$C:T_c\left(X\right)<T_c\left(Y\right)$

Select the correct alternate.

A small source of sound oscillates in simple harmonic motion with an amplitude of 17 cm. A detector is placed along the line of motion of the source. The source emits a sound of frequency 800 Hz which travels at a speed of $340m{s}^{-1}$. If the width of the frequency band detected by the detector is 8 Hz, find the time period of the source.

As shown in figure, a wheel $(r=1\text{m})$ is performing combined translational and rotational motion with angular velocity $2\text{rad/s}$ and the velocity of its centre as $\overrightarrow{V_O}=4\hat{i}\text{m/s}$. Find the velocity of point $B$ in $\text{m/s}$ on the wheel.

Two speakers S, and S2, driven by the same amplifier, are placed at y =1.0 m and y = -1.0 m (figure 16-E4). The speakers vibrate in phase at 600 Hz. A man stands at a point on the X-axis at a very large distance from the origin and starts moving parallel to the Y-axis. The speed of sound in air is 330 m/s. (a) At what angle $\theta$ will the intensity of sound drop to a minimum for the first time ? (b) At what angle will he hear a maximum of sound intensity for the first time ? (c) If he continues to walk along the line, how many more maxima can he hear ?

.A block of mass 5.0 kg is suspended from the end of a vertical spring which is stretched by 10 cm under the load of the block. The block is given a sharp impulse from below so that it acquires an upward speed of 2.0 m/s. How high will it rise ? Take g = $10m/s^2$

3. When a projectile is at the highest point on its trajectory, the potential and kinetic energies are respectively a) maximum and minimum b) minimum and zero c) zero and maximum d) maximum and zero

4. A block of mass 2 kg starts moving when the angle of inclination of the inclined plane is 60o . If the coefficient of kinetic friction is 0.6, the frictional force is a) 2 N b) 1 N c) 4 N d) 0.5 N 5. Two forces F1 = (7i + 2j) N and F2 = (-5i + 3j) N act on a particle. The third force F3 that should act on the particle to make it move with constant velocity is a) (2i + 5j) N b) (-2i – 5j) N c) (–2i + 5j) N d) (2i – 5j) N 6. Two satellites of masses 3M and M orbit the earth in circular orbits of radii r and 3r respectively. The ratio of their speeds is a) 1 : 1 b) : 1 c) 3 : 1 d) 9 : 1 7. In an adiabatic process, the pressure of a gas is proportional to the cube of its absolute temperature. The value of (which equals Cp/Cv) is a) 5/4 b) 4/3 c) 5/3 d) 3/2 Space for rough work AEE15vA 4 8. A mass is moving towards the origin along the x-axis with constant velocity. Its angular momentum with respect to the origin a) remains constant b) is zero c) increases d) decreases 9. The rate of cooling of a liquid is 4o C/s, when its temperature is 80o C and is 2o C/s when its temperature is 50o C. The temperature of the surrounding is a) 30o C b) 20o C c) 10o C d) 25o C 10.A Charged sphere of radius 1m carries a charge of 1 x 10-9 C. The electric fields at a point P, which is at a distance d = 3m from the centre of the sphere and at a point Q, at a distance d = 0.3m from the centre of the sphere are respectively a) 1 N/C and 100 N/C b) 1 N/C and zero c) zero and 1 N/C d) 1 N/C and 3 N/C 11.An electric dipole lying along X-axis with moment 5 Am2 is subjected to an electric field of magnitude 10j N/C. The torque experienced is a) 2 Nm b) 10 Nm c) 50 Nm d) 25 Nm 12.A parallel plate capacitor with air gap of 5 mm is 2 MFD. If a metallic plate of thickness 3 mm is inserted in between the plates, the new capacitance is a) 5 MFD b) 1 MFD c) 2 MFD d) 2.5 MFD 14. Two resistances 6Ω and 3Ω are connected in parallel and this combination is connected in series with a 4Ω resistance. This combination is powered by a voltage source of 12 V and zero internal resistance. The ratio of power dissipated between 6Ω resistance and 4Ω resistance is a) 1:4 b) 4:1 c) 1:8 d) 3:215. Two charged particles of charge ratio 1:4 moving with same velocity enter a region of uniform magnetic field of strength B and get deflected and move along curves with equal radius R. The ratio of their masses is a) 4:1 b) 2:1 c) 1:4 d) 1:2 16. When a charged particle moves in a region with electric field E = 3i N/C and magnetic field B = 5j T, the trajectory of the particle is a) circle b) parabola c) straight line d) helix 17. Two co-axial coils A and B of radius R1 and R2 carry equal amount of current but flowing in opposite direction. The net magnetic field produced at the centre of these coils is zero. The ratio of the current flowing in the coil A to current in coil B is a) R1 : R2 b) R2 : R1 c) (R2 / R1) 2 d) (R1 / R2) 2 20.An object of size 10 cm is kept at a distance of 10 cm from a convex lens. If the focal length of the lens is 5 cm, the size of the image is a) 10 cm b) 20 cm c) 5 cm d) 15 cm 21.A biconvex lens of focal length 10 cm is to be made from a glass material. If the refractive index of the material is 1.5, what must be the radius of curvature of the surface of the lens? a) 0.1 m b) 0.15 m c) 0.20 m d) 0.30m22.A diffraction grating with 106 lines / m is used to determine the wavelength of a monochromatic source. The angle of first order diffraction is 30o . The wavelength of the source is a) 1000 nm b) 500 nm c) 400 nm d) 600 nm 23.A glass plate of thickness 1.5 μm and refractive index 1.5 is introduced between one of the slits and screen in a Young’s double slit experiment. If the wavelength of the monochromatic source used is = 0.75 μm, the phase difference between the interfering waves at the centre of the screen is equal to a) 6 b) 3 c) d) 2 24. What is the velocity of light in a medium with refractive index 1.5? a) 2 x 108 m/s b) 3 x 108 m/s c) 1.5 x 108 m/s d) 2.5 x 108 m/s 25. Which among the following electromagnetic radiations is the most energetic? a) Infra red light b) Visible light c) Ultraviolet light d) microwaves 26. Which of the following particles has the shortest de-Broglie wavelength, if all of them move with same speed? a) beta particle b) alpha particle c) proton d) neutron 27. The mass of a photon of wavelength is given by a) h /c b) /hc c) h/ c d) hc/ 28. The radius of a nucleus with A = 256 is 8 fermi (1 fermi = 1 x 10-15 m). The radius of a nucleus with A = 4 is a) 1 fermi b) 2 fermi c) 3 fermi d) 4 fermi 29. Photons of energy 6 eV fall on the surface of a metal with work function 4 eV. The stopping potential of the metal surface is a) 2 V b) 10 V c) 3 V d) 1 V

A pulley wheel of diameter $10\text{cm}$ has a $1\text{m}$ long cord wrapped around its periphery. The wheel is initially at rest. Assuming angular acceleration of wheel to be uniform and the time taken for the cord to unwind completely to be $18\text{s}$, find its tangential acceleration.

An object is displaced from position vector $\overrightarrow{r_1}=2\hat{i}+3\hat{j}\left(m\right)$ to $\overrightarrow{r_2}=4\hat{j}+6\hat{k}\left(m\right)$ under a force

$\overrightarrow{F}=3x^2\hat{i}+2y\hat{j}$. Find out the work done by the force.

Two springs of force constants $k_1$ and $k_2$ are connected as shown figure. The time period of vertical oscillations of mass m is given by

In the figure shown, the acceleration of A is $2m/s^2$ to left and acceleration of B is 1 $m/s^2$ to left.

Find the magnitude of acceleration of C in $m/s^2$

A horizontal pipeline carries water in a streamline flow. At a point where the cross-sectional area is $10{\text{cm}}^2$, the water velocity is $1{\text{ms}}^{-1}$ and pressure is $2000\text{Pa}$. The pressure of water at another point where the cross sectional area is $5{\text{cm}}^2$, is: