List of top Questions asked in KEAM- 2020

The electric flux (in SI units) through any face of a cube due to a positive charge \(Q\) situated at the centre of the cube is

A capacitance of a parallel plate air capacitor is \(10\mu\text{F}\). Dielectric constant of the medium to be introduced in between its plates is to double its capacitance is

In a platinum resistance thermometer, the resistance of the wire at ice point and steam point are respectively \(4.2\ \Omega\) and \(4.25\ \Omega\). When the thermometer is kept in a hot water bath, the resistance of the wire is found to be \(4.5\ \Omega\). The temperature of the hot water bath is

A steady current flows in a metallic conductor of non-uniform cross section. The quantity/quantities that remain/remains constant along the length of the conductor is/are

An observer, moving in a straight line with velocity \(100\ \text{m s}^{-1}\), passes a stationary observer. If the object emits note of \(400\) Hz while moving, the change in the frequency noticed by the observer as the object passes past him is \((\text{speed of sound in air}=300\ \text{m s}^{-1})\)

Two strings of the same material and same length are given equal tension. If they are vibrating with fundamental frequencies \(1600\) Hz and \(900\) Hz, then the ratio of their respective radii is

Two simple harmonic motions with the same amplitude and same frequency acting in the same direction are impressed on a particle. If the resultant amplitude of the particle is twice the amplitude of individual S.H.Ms, the phase difference between the two simple harmonic motions is

Two shortest harmonics of an organ pipe open at both ends are \(200\) Hz and \(240\) Hz. The fundamental frequency is

A travelling wave in a medium is given by the equation \(y=a\sin(\omega t-kx)\). The maximum acceleration of the particle in the medium is

Three moles of an ideal gas are in a rigid cubical box with sides of length \(0.170\) m. The ratio of the forces that the gas exerts on each of the six sides of the box when the temperature are \(27^\circ\)C and \(127^\circ\)C is

The average kinetic energy of a monoatomic gas molecule kept at temperature \(27^\circ\)C is \((\text{Boltzmann constant}=1.3\times 10^{-23}\ \text{J K}^{-1})\)

Two taps supply water to a container, one at the temperature of \(20^\circ\)C at the rate of \(2\) kg/minute and another at \(80^\circ\)C at the rate of \(1\) kg/minute. If the container gets water from the taps simultaneously for \(10\) minutes, then the temperature of water in the container is

The density of kerosene is \(800\ \text{kg m}^{-3}\). Its relative density is

A solid sphere of volume \(V\) experiences a viscous force \(F\) when descending with a speed \(v\) in a liquid. If another solid sphere of volume \(27V\) descends with the same speed \(v\) in the same liquid, it experiences a viscous force

If a monoatomic gas is compressed adiabatically to \((1/27)^{\text{th\) of its initial volume, then its pressure becomes}

The values of \(C_V\) and \(C_P\) for a diatomic gas are respectively \((R=\) gas constant\()\)

Two identical objects each of mass \(50\) kg are kept at a distance of \(50\) cm apart on a horizontal table. The net gravitational force at the mid-point of the line joining their centres is

The ratio of the weight of a body at a height of \(\dfrac{R}{10}\) from the surface of the earth to that at a depth of \(\dfrac{R}{10}\) is \((R\) is radius of earth\()\)

Three thin wires of equal length in suspension have the respective ratio of their area of cross section \(1:2:4\) and Young's moduli \(4:2:1\), then the ratio of their time periods due to attached at the other ends due to elongation is

If the distance between sun and earth is \(d\), then the angular momentum of earth around the sun is proportional to

If a ring rolls down from top to bottom of an inclined plane, it takes time \(t_1\). If it slides, it takes time \(t_2\). Then the ratio \(\dfrac{t_1}{t_2}\) is

Water flows through a horizontal pipe of diameter \(2\) cm at speed of \(3\ \text{cm s}^{-1}\). The pipe has a nozzle of diameter \(0.5\) cm at its end. The speed of water emerging from the nozzle is

Four particles of masses \(m_1=1\) kg, \(m_2=2\) kg, \(m_3=1\) kg and \(m_4=m\) are placed at the four corners of a square. The mass \(m_4\) required, so that the centre of mass of all the four particles is exactly at the centre of the square is

A body of mass \(2\) kg is moving with a momentum of \(10\ \text{kg m s}^{-1}\). The force needed to increase its kinetic energy four times in \(10\) seconds is

If a force \(\vec{F}=\hat{i}-2\hat{j}-4\hat{k}\) acting on a particle displaces it from \((1,1,1)\) to \((2,-1,0)\), then the work done by the force (in units of work) is