Explore topic-wise InterviewSolutions in Current Affairs.

If the angles of dip at two places are ${30}^{\circ }$ and ${45}^{\circ }$ respectively, then the ratio of horizontal components of earth's magnetic field at the two places will be

A plano-convex lens $\text{P}$ and a concavo-convex lens $\text{Q}$ are in contact as shown in figure. The refractive index of the material of the lens $\text{P}$ and $\text{Q}$ are $1.8$ and $1.2$ respectively. The radius of curvature of the concave surface of the lens $\text{Q}$ is double the radius of curvature of the concave surface. The convex surface of $\text{Q}$ is silvered. The radius of curvature of common surface if focal length of the system is $-8\text{cm}$ will be

Two stars each of one
solar mass (= 2× 10³⁰ kg) are approaching each other
for a head on collision. When they are a distance 109 km, their
speeds are negligible. What is the speed with which they collide? The
radius of each star is 104 km. Assume the stars to remain undistorted
until they collide. (Use the known value of G).

The velocity of waves in a string fixed at both ends is 2 m/s. The string forms standing waves with nodes 5.0 cm apart. The frequency of vibration of the string in Hz is

[SCRA 1998]

Plot of Maxmell’s distribution of velocities is given below:

Which of the following is correct about this plot?

If vectors $\overrightarrow{a},\overrightarrow{b}$ and $\overrightarrow{c}$ are such that $|\overrightarrow{a}|=1,|\overrightarrow{b}|=2$ and $|\overrightarrow{a}-\overrightarrow{b}{|}^2+|\overrightarrow{a}+2\overrightarrow{b}{|}^2=20,$ then angle between vectors $\overrightarrow{a}$ and $\overrightarrow{b}$ is

1. 104.719

A block of mass $m$ is kept on an inclined plane inside a lift moving down with acceleration of $2{\text{m/s}}^2$. What should be the coefficient of friction between block and inclined plane to let the block move down with constant velocity relative to lift?
(Take $g=10{\text{m/s}}^2$)

A ball after freely falling from a height of $4.9\text{m}$ strikes a fixed horizontal plane. If the coefficient of restitution is $\frac{3}{4}$, after what time interval the ball will strike the plane second time :

Two rods having same length and cross-sectional area are connected individually between temperature $T_1$ and $T_2$. If the rate of loss of heat due to condution is equal and specific heat of two rods are in the ratio $1:2$, then the ratio of their thermal conductivity will be

A current carrying loop is placed in a uniform magnetic field in four different orientation:I,II, III & IV. Arrange them in the decreasing order of their potential Energy.

If the molar heat capacity of the given process is $C$, then

A block Q of mass $M$ is placed on a horizontal frictionless surface AB and a body P of mass $m$ is released on its frictionless slope. As P slides by a length $L$ on this slope of inclination $\theta$, the block Q would slide by a distance

A rough casting of a rotor, with a mass of 200 kg, is mounted on centres 110 cm apart for machining. The rotor is statically balanced by attaching two masses, one each in the planes A (9 kg) and B (12 kg), which are on opposite sides of the plane containing the mass centre of the rotor, at a distance of 50 cm and 35 cm respectively from it. The angle between the CG of the plane A and that of the plane B is 90${}^{\circ }$. The distance of each mass from the axis of rotation is 37 cm (for the plane A) and 44 cm (for the plane B).



The distance of the CG of the rotor from the axis of rotation, and its angular position with respect to the mass in the plane A respectively are

A laser beam has intensity $2.5\times {10}^{14}$${\text{Wm}}^{-2}$. The amplitudes of electric and magnetic fields in the beam are :

A straight solenoid has $50$ turns in the primary coil and $200$ turns in the secondary coil. The area of cross-section of the solenoid is $4{\text{cm}}^2$ and length is $4\pi \text{cm}$. The mutual inductance, if primary coil is tightly kept co-axial inside the secondary coil, is



Assume almost equal cross-sectional area and length.

1. 120.12

If the arcs of the same length in two circles subtend angles ${65}^{\circ }and{110}^{\circ }$ at the centre, then the ratio of the radii of the circles is

A coil $\text{A}$ of radius $R$ and number of turns $n$ carries a current $i$ and it is placed in a horizontal plane. A small conducting ring $\text{P}$ of radius $r(r<<R)$ is placed at a height $y$ above the centre of the coil $\text{A}$ as shown in the figure. Calculate the induced $\text{emf}$ in the ring when the ring is allowed to fall freely. Express the induced $\text{emf}$ as a function of instantaneous speed $v$ of the falling ring and its height $y$ above the centre of the coil $\text{A}.$

A system consists of block A and B of same mass $5kg$ and connected to the pulley as shown in figure. Find the relative acceleration with which they will move?

(Take $g=10m/s^2$)

Q. A particle start from rest and transverse a distance L with uniforms acceleration,then moves uniformly over a further distance 2L and finally comes to rest after moving a further distance 3L under uniform retardation. Assuming entire motion to be rectilinear motion the ratio of average speed over journey to the maximum speed on its ways is

Which one of these first -order logic formulae is valid?

Which logic gate is represented by the following combination of logic gates ?

Consider the following statement: When jumping from some height, you should bend your knees as you come to rest, instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement

Evaluate: $\int \frac{2zdz}{\sqrt[3]{3z^2+1}}$

A ring of mass m and radius 'r' is mounted on a light rod which is suspended by means of two string. Find the tension in the strings if the ring carries a current i and a vertical magnetic field $\beta$ exists. Given

$(\frac{i{a}^{2}B}{l}=\frac{mg}{2\pi })$.

A physical quantity $z$ depends on four observables $a,b,c$ and $d$ , as $z=\frac{a^2{b}^{\left(2/3\right)}}{\sqrt{c}{d}^3}$. The percentages of error in the measurement of $a,b,c$ and $d$ are $2\%,1.5\%,4\%$ and $2.5\%$ respectively. The percentage of error in $z$ is

How much work must be done to pull apart the electron and the proton with almost negligible kinetic energies that make up the Hydrogen atom, if the atom is initially in the state with $n=2$?

In galvanometer, the deflection becomes the half when its is shunted by a $20\Omega$ resistor. The galvanometer resistance is ?

A cube of iron whose sides are of length $L$, is floating in a beaker containing mercury. The weight of iron cube is $W$. The density of iron is ${\rho }_I$ and that of mercury is ${\rho }_M$. The depth to which the cube sinks is given by the expression

A battery is connected to a potentiometer and the balance point is obtained at $84\text{cm}$ along the wire. When its terminals are connected by a $5\Omega$ resistor, the balance point changes to $70\text{cm}$.



$\left(ii\right)$ Find the new position of the balance point when $5\Omega$ resistor is changed by $4\Omega$ resistor.



​​​​​​​$[$1 Mark$]$

For the force-displacement graph for a particle is as shown below. If the particle has mass of $2\text{kg}$ and has initial velocity of $2\text{m/s}$, calculate final kinetic energy of particle, when it displaces from $x=1\text{m}$ to $x=5\text{m}$.

A wire has a resistance of 6 ohms. It is bent in the form of an equilateral triangle. The effective resistance between any two corners of the triangle is

Twelve wires, each having equal resistance of 2 $\Omega$, are joined to form a cube. What is the equivalent resistance between the ends of a face diagonal?