Explore topic-wise InterviewSolutions in Current Affairs.

The ratio of change in the base-emitter voltage (ΔV_BE) to the resulting change in base current(ΔI_B), at a constant collector-emitter voltage (V_CE) is defined as :

A tank is filled with water upto a height of $8\text{m}$. A hole $P$ is made in the wall of tank such that water coming out of it travels maximum horizontal distance. Find the speed of water coming out of hole $P$.

A bob of mass 0.1 kg hung from the ceiling of a room by a string 2 m long is set into oscillation. The speed of the bob at its mean position is $1m{s}^{-1}$. What is the trajectory of the bob if the string is cut when the bob is (a) at one of its extreme positions, (b) at its mean position.

The root mean square velocity of one mole of a monoatomic gas having molar mass M is $U_{rms}$. The relation between the average kinetic energy (E) of the gas and $U_{rms}$ is :

The amplitude of a particle executing S.H.M. with frequency of 60 Hz is 0.01 m. The maximum value of the acceleration of the particle is

[DPMT 1998; CBSE PMT 1999; AFMC 2001;

Pb. PMT 2001; Pb. PET 2001, 02; CPMT 1993, 95, 04;

RPMT 2005; MP PMT 2005]

A 1 kg stone at the end of 1 m long string is whirled in a vertical circle at constant speed of 4 m/sec. The tension in the string is 6 N, when the stone is at (g = 10 m/$se{c}^2$)

The coefficient of restitution 'e' for a perfectly inelastic collision is

Two bodies are thrown with the same initial velocity at angles $\theta$ and $({90}^{\circ }-\theta )$ respectively with the horizontal, then their maximum heights are in the ratio:

A man places a chain (of mass ${}^{\prime }{m}^{\prime }$ and length ${}^{\prime }{L}^{\prime }$) on a table slowly. Initially the lower end of the chain just touches the table. The man drops the chain when half of the chain is in vertical position. Then work done by the man in this process is:

A block with initial velocity $2\text{m/s}$ is sliding on a horizontal frictionless surface as shown in the figure. What is the value of $\theta$ when the block leaves the surface?

CP: Given position time graph of a particles motion along x-axis

Q: At what time t is the particle moving towards the starting point?

Two cylinders $A$ and $B$ fitted with pistons contain equal amounts of an ideal diatomic gas at $300\text{K}$. The piston of $A$ is free to move, while that of $B$ is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in $A$ is $30\text{K}$, then the rise in temperature of the gas in $B$ is

Einstein's photoelectric equation states that $E_k=hv-\varphi$. In this equation $E_k$ refers to

A cylindrical tank of height 0.4 m is open at the top and has a diameter of 0.16 m. It is filled with water upto a height of 0.16 m. Find the time taken to empty the tank through a hole of radius 5 x 10^-3 m in its bottom.

A particle returns to the starting point after $10\text{s}$. if the rate of change of velocity during the motion is constant, then its location after $7\text{s}$ will be same as that after

Wave length of the light is 6000 Å , then

When you drop a ball you find that the ball accelerates towards the Earth due to the mutual gravitational force experienced. By Newton’s third law, the Earth also should experience an equal and opposite force. Why do we not see the Earth accelerating towards the ball?

A particle, which is constrained to move along the x - axis the x - axis, is subjected to a force in the same direction which varies with the distance x of the particle from the origin as $F\left(x\right)=-kx+a{x}^3$. Here k and a are positive energy U(x) of the particle is

At a given tempreture, the pressure of an ideal gas of density $\rho$ is proportional to

In isothermal expansion, the pressure is determined by

A force of 750 N is applied to a block of mass 102 kg to prevent it from sliding on a plane with an inclination angle ${30}^o$ with the horizontal. If the coefficients of static friction and kinetic friction between the block and the plane are 0.4 and 0.3 respectively, then the frictional force acting on the block is

As we go from the equator to the poles, the value of g

A body is sliding down an inclined plane having coefficient of friction 0.5. If the normal reaction is twice that of the resultant downward force along the incline, the angle between the inclined plane and the horizontal is

Block A is heavier than Block B, and when they are put on a wedge connected through a pulley, they start sliding. Identify the direction of friction on both the blocks.

A force of 5 N acts on a body of weight 9.8 N. What is the acceleration produced in $m/se{c}^2$

A charge of $+2.0\times {10}^{-8}C$ is placed on the positive plate and a charge of $-1.0\times {10}^{-8}C$ on the negative plate of a parallel-plate capacitor of capacitance $1.2\times {10}^{-3}\mu F.$

Calculate the potential difference developed between the plates.

Which of the following graphs shows the variation of magnetic induction B with distance r from a long wire carrying current

[NCERT 1984; MNR 1998; MP PMT]

A jar is filled with two non-mixing liquids having densities ${\rho }_1$ and ${\rho }_2$ respectively. A solid ball, made of a material of density ${\rho }_3$, is dropped in the jar. It attains equilibrium in the position as shown in the figure. Which of the following is true for ${\rho }_1,{\rho }_2$ and ${\rho }_3$ ?

When wavelength of incident photon is decreased then

The potential energy between two atoms in a molecule is gives by, U (x) = $\frac{a}{x^{12}}$ - $\frac{b}{x^6}$ , where a and b are postive constant and x is the distant between the atome. The system is in stable equilibrium when

A longitudinal wave propagating in a water-filled pipe has intensity $3.00\times {10}^{-6}\frac{w}{m^2}$ and frequency 3400 Hz. Water has density $1000\frac{kg}{m^3}$ and bulk modulus $2.18\times {10}^9$ Pa. If the pipe is then filled with air at pressure $1.00\times {10}^5$ Pa and density $1.20\frac{kg}{m^3}$, and the a wave with the same intensity and frequency is propagated, What is the ratio of the two amplitudes in both media?

Two rods $\text{OA}$ and $\text{OB}$ of equal lengths and masses are lying in the $xy$ plane as shown in figure. Let $I_x,I_y$ and $I_z$ be the moments of inertia of both the rods about $x,y$ and $z$ axis respectively. Then,

The springs shown in the figure are all unstretched in the beginning when a man starts pulling the block. The man exerts a constant force F on the block. Find the amplitude and the frequency of the motion of the block.

Which of the following values are incorrect for the cyclic process?

The temperature of a body falls from 40${}^{\circ }$C to 36${}^{\circ }$C in 5 minutes when placed in a surrounding of constant temperature 16${}^{\circ }$C. Find the time taken for the temperature of the body to become 32${}^{\circ }$C.

How much energy is required to excite an electron from $n_1=1$ to $n_2=2$ in a hydrogen atom? [Given : IE of hydrogen atom is $1.312\times {10}^{6}J\left(mol\right)]$

A particle with ${10}^{-11}$ coulomb of charge and ${10}^{-7}$ kg mass is moving with a velocity of ${10}^8$ m/s along the y-axis. A uniform static magnetic field B = 0.5 T is acting along the x-direction. The force on the particle is

A thin circular loop of radius R rotates about its vertical diameter with an angular frequency $\omega$. Show that a small bead on the wire loop remains at its lowermost point for $\omega \le \sqrt{\frac{g}{r}}$. What is the angle made by the radius vector joining the centre to the bead with the vertical downward direction for $\omega =\sqrt{\frac{g}{r}}$? Neglect friction.

The equation $△x.△p\ge \frac{h}{4\pi }$

The uncertainty in the position of a moving bullet of mass 10 gm is ${10}^{-5}$ m. Calculate the uncertainty in its velocity

To convert a fraction to percent, multiply by ___.

A body slipping on a rough horizontal plane moves with a deceleration of 4.0 $m/s^2$ With a deceleration of kinetic friction between the block and the plan?

The number of moles of electrons passed when a current of 2 A is passed through a solution of an electrolyte for 20 minutes is: