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The potential difference between the terminals of a 6.0 V battery is 7.2 V when it is being charged by a current of 2.0 A. What is the internal resistance of the battery ?

Two metals A and B have work function 4 electron volts and 10 electron volts respectively, Which metal has higher threshold wavelength?

10kg block is kept on a horizontal surface and Ram is trying to pull it with a force of 5N, Given coefficient of static friction is 0.2 and coefficient of Kinetic friction n(μK) = 0.1 Which of these statements is/are correct.

A particle is projected from point $\text{O}$ on the ground with velocity $u=5\sqrt{5}\text{m/s}$ at angle $\alpha ={\tan }^{-1}\left(0.5\right)$. It strikes at point $\text{C}$ on a fixed smooth plank $\text{AB}$ having inclination ${37}^{\circ }$ with horizontal as shown in figure. If the particle does not rebound, the co-ordinate of point $\text{C}$ in reference to co-ordinate system as shown in the figure is

(Given that $OA=\frac{10}{3}\text{m}$)

In the given circuit, the potential difference between Q and S is

A car of mass $50\text{kg}$ is travelling at a speed of $20\text{m/s}$ on a circular road of radius $30\text{m}$ having angle of banking equal to ${53}^{\circ }$. If the coefficient of static friction between the road and the tyres is $0.4$, then find the value of frictional force acting on the car. Take $g=10{\text{m/s}}^2$.

A train is moving towards north. At one place it turns towards north-east, here we observe that

A rectangular block is heated from $0^{\circ }\text{C}$ to ${100}^{\circ }\text{C}$. The percentage increase in its length is $0.10\%$. What will be the percentage increase in its volume?

The brakes applied to a bike produce retardation of $5{\text{m/s}}^2$. If the bike takes $4\text{s}$ to stop after the application of brakes, calculate the distance it travels during this time.

The moment of inertia of thin square plate ABCD of uniform thickness about an axis passing through the centre O and perpendicular to the plane of the plate is not equal to (Given $I_1,I_2,I_{3}and{I}_4$ respectively, are the moments of inertia about axes 1,2,3and 4 which are in the plane of the plate)

For the rotating container shown in figure, differences in the heights of the fluid between the centre and the sides (in $\text{cm}$) is-

[Take ${\pi }^2=10\&g=10{\text{m/s}}^2$ for calculation]

Careful
measurement of the electric field at the surface of a black box
indicates that the net outward flux through the surface of the box is
8.0 × 10³
N m²/C.
(a) What is the net charge inside the box? (b) If the net outward
flux through the surface of the box were zero, could you conclude
that there were no charges inside the box? Why or Why not?

A particle is projected with velocity of $u=30\hat{i}+40\hat{j}$ . Its velocity (in $m/s$) after $2$ seconds is

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

Through two parallel wires x and y, currents of 10A and 2A, respectively are passed in opposite directions. X is infinitely long and y has a length of 2m. The distance between them is 10cm. The magnetic force on y is

Find the projection of $\overrightarrow{A}=2\hat{i}-\hat{j}+\hat{k}$ along the vector $\overrightarrow{B}=\hat{i}+\hat{j}+\hat{k}$.

Two beams $A$ and $B$ of plane polarized light with mutually perpendicular planes of polarization are through a polaroid. From the position when the beam $A$ has maximum intensity (and beam $B$ has zero intensity), a rotation of polaroid through ${30}^{\circ }$ makes the two beams appear equally bright. If the initial intensities is of the two beams are $I_A$ and $I_B$ respectively, then $\frac{I_A}{I_B}$ is equal to,

A boy is moving along a circular track in an anticlockwise sense. A girl moves along a regular hexagonal path. The centres of hexagonal track and a circular track coincide as shown in the figure. The girl and the boy starts from point B and A such that P, A & B always lie on the same radial line. The velocity of the boy is 1m/s. Given side length of regular hexagon is "a" and radius of circular path is $\frac{a}{\sqrt{3}}$. The speed of Girl at point C is___

A tiny spherical oil carrying a net charge $q$ is balanced in still air with a vertical uniform electric field of strength $\frac{81\pi }{7}\times {10}^5{\text{V m}}^{-1}$. When the field is switched off, the drop is observed to fall with terminal velocity $2\times {10}^{-3}{\text{ms}}^{-1}$. Given, $g=9.8{\text{ms}}^{-2}$, viscosity of the air $=1.8\times {10}^{-5}{\text{Ns m}}^{-2}$ and the density of oil $=900{\text{kg m}}^{-3}$, the magnitude of $q$ is

Three charges are arranged on the vertices of an equilateral triangle as shown in figure. Find the magnitude of dipole moment of the combination.

A projectile is fired from the top of a 40 m high cliff with an initial speed of 50 m/s at an unknown angle. Find its speed when it hits the ground

Assuming all the surfaces to be frictionless, the acceleration of block $C$ shown in the figure is

A uniform conducting rectangular loop of sides $l$, $b$ and mass $m$ carrying current $i$ is hanging horizontally with the help of two vertical strings. There exists a uniform horizontal magnetic field B which is parallel to the longer side of the loop. The value of tension which is least is

A ball is thrown at an angle x and another ball is thrown at angle (90°-x) with horizontal direction from the same point with velocity 40 m/s. The second ball reaches 50 m higher than the first ball. Find their individual heights. g=10m/s2

An infinitely long hollow conducting cylinder with inner radius $\frac{R}{2}$ and outer radius R carries a uniform current density along its length. The magnitude of the magnetic field $|B|$ as a function of the radial distance $r$ from the axis is best represented by

If $|\overrightarrow{a}+\overrightarrow{b}|=|\overrightarrow{a}-\overrightarrow{b}|$, then

(a) In a liquid with density $1300kg/m^3$, longitudinal waves with frequency 400Hz are found to have wavelength 4m. calculate the bulk modulus of the liquid.

(b) A metal bar with a length of 2m has density $6400kg/m^3$. Longitudinal sound waves take $3.90\times {10}^{-4}$s to travel from one end of the bar to the other. What is Young’s modulus for this metal?

For a given gas at 1 atm pressure, rms speed of the molecules is 200 m/s at ${127}^{\circ }C.$ At 2 atm pressure and at ${227}^{\circ }C$, the rms speed of the molecules will be:

From given figure find charge flown through $A$ to $B$ when switch $S$ is closed.

In npn transistor circuit, the collector current is $20\text{mA}$. If $80\text{\%}$ of the electrons emitted reach the collector, the emitter current will be