List of top Questions asked in KEAM

The greatest wavelength of the radiation that will ionize unexcited hydrogen atom is

The half-life periods of two radioactive materials A and B are 1500 years and 1200 years respectively. If their mean life periods are \( \tau_A \) and \( \tau_B \) respectively, then the value of the ratio \( \frac{\tau_A}{\tau_B} \) is

If \( \lambda \) be the wavelength of any electromagnetic radiation, the de-Broglie wavelength of its quantum (photon) is

Pick out the INCORRECT statement from the following:

In Young's double slit experiment, the band width of the fringes observed is \( \beta \), when light of wavelength \( \lambda \) is used. With same experimental set up, to double the band width of the fringes, the wavelength of light required is

The Brewster's angle \( i_B \) for any interface should lie between

When a ray of light moves from one medium to another medium,

If \( v_g, v_X \) and \( v_v \) are the speeds of gamma rays, X-rays and visible light respectively in vacuum, then

An alternating current having the peak value \( 10\sqrt{2}\,\text{A} \) is used to heat a metal wire. To produce the same heating effect, the constant current required is

The self-inductance of an air core solenoid is \( L \). If the number of turns in the solenoid is doubled, keeping all other factors constant, then its self-inductance will be

If a magnetic material has magnetic susceptibility \( \chi = -0.5 \), then its relative magnetic permeability \( \mu_r \), and the type of material is

A galvanometer of resistance \( 100\Omega \) gives a full scale deflection for a current of \( 1\,\text{mA} \). The resistance required to convert it into a voltmeter which can read up to \( 2\,\text{V} \) is

In a cyclotron, if the frequency of the accelerating field is doubled, then the radius of the charged particle moving in a circular path will be

When \( n \) identical cells are connected in parallel,

If an equilateral triangle is made of a uniform wire of resistance \( R \), then the equivalent resistance between the ends of a side is

The dependence of drift velocity \( v_d \) on the electric field \( E \), for which Ohm's law is obeyed is

A given charge \( Q \) is divided into two parts which are then kept at a distance \( d \) apart. The electrostatic force between them will be maximum if the two parts are

In a circuit, the capacitance \( C \) is connected. The effective capacitance of the circuit can be reduced by

The inward and outward electric flux from a closed surface are \( 6\times10^4 \,\text{Nm}^2\text{C}^{-1} \) and \( 3\times10^4 \,\text{Nm}^2\text{C}^{-1} \). Then the net charge (in coulomb) inside the closed surface is

A string of length \( l \) is divided into three segments of lengths \( l_1, l_2 \) and \( l_3 \) with the fundamental frequencies \( n_1, n_2 \) and \( n_3 \) respectively. The original fundamental frequency of the string is given by

Time periods of pendulums \( A \) and \( B \) are \( T \) and \( \frac{5T}{2} \). If they start executing S.H.M. at the same time from the mean position, the phase difference between them after the bigger pendulum has completed one oscillation is

The distance travelled by a particle executing linear S.H.M. from its mean position in 2 s is equal to \( \frac{1}{\sqrt{2}} \) times its amplitude. Then its time period in seconds is

Pick out the INCORRECT STATEMENT

The number of degrees of freedom for monoatomic gas molecule is

A cylindrical vessel contains 16 kg of gas at a pressure of 1 atmosphere. A certain amount of gas is taken out and the pressure of gas in the vessel becomes 0.75 atmosphere. The amount of gas taken out is