List of top Questions asked in KEAM

A radioactive nuclei has a half life of 693s. The activity of one mole of that nuclei sample is:(Avogadro's number=6.023 x1023 and In(2)=0.693) 

A gun fires N bullets per minute. The mass of each bullet is 10g and every bullet travels With a speed of 600m/s. If the power delivered by the gun is 9000W,the value of N is:

A glass capillary of radius 0.15 mm is dipped into a liquid of density and surface tension 1600 kg/m3 and 0.12 Nm-1,respectively. The liquid in the capillary rises by a height of 5.0 cm. The contact angle between liquid and glass will be:(Take g=10 ms-2)

A body undergoing a straight line motion is under the influence of source of constant power. How does its displacement very with time?

The angle of minimum deviation for a prism of apex angle 60° and refractive index of \(\sqrt{2}\) is:

Select the incorrect statement about friction:
A metal wire of natural length 50cm and cross-sectional area 4.0 mm2 is fixed at end. A mass of 2.4kg is hung from the other end of the wire. If the elastic pot energy of the wire is 1.8x10-4J,then its Young's modulus is:(Take g=10 ms-2)
An ideal gas is kept in a closed container. If the temperature is doubled and the volume of the container is reduced to half, the gas pressure is:
An average frictional force of 80N is required to stop an object at a distance of 25m. If the initial speed of the object is 20m/s,the mass of the object is:
In a Zener regulated power supply circuit as shown in figure below,a Zener diode with Vz=1OV is used for regulation. The load current,Zener current and unregulated input Vin are 5mA,35mA and 20V,respectively. The value of R is:
A planet has an escape speed of 10km/s,The radius of the planet is 10,000km. The acceleration due to gravity of the planet at its surface is:
A wheel is rolling on a plane surface. A point on the rim of the wheel at the same level as the Centre has a speed of 4m/s. The speed of the Centre of the wheel is:
A uniform thin rod of mass 3kg has a length of 1m. If a point mass of 1kg is attached to it at a distance of 40cm from its center,the center of mass shifts by a distance of: 

A train consists of an engine and 3 coaches, first coach is closest to the engine, third coach is farthest from engine. The train is moving with a constant acceleration a. The mass of each coach is M. The force exerted by the first coach on the second coach will be:

N capacitors,each with 1μF capacitance,are connected in parallel to store a charge of 1C. The potential across each capacitor is 100V. If these N capacitors are now connected in series,the equivalent capacitance in the circuit will be:

A horizontal force is exerted on a 20 kg box to slide it up on an inclined plane with an angle of 30°. The frictional force retarding the motion is 80 N. If the box moves with a constant speed, then the magnitude of the force is:(Take g=10 ms-2)

Suppose a force is given by the expression=kx2;where x has the dimension of length.The dimension of k is:

For the hydrogen spectrum,the wavelength in Balmer series is given by \(\frac{1}{λ}\)=R(\(\frac{1}{n_{1}^{2}}\)-\(\frac{1}{n_{2}^{2}}\)) where λ= wavelength and R is Rydberg constant. What are the values of n1 and n2,for the longest wavelength in the Balmer series?

A laser source emits light of wavelength 300nm and has a power of 3.3mW. The average number of photons emitted per second is:(Speed of light-3x108m/s,Plank's constant 6.6 x 10-34J/s)

What is the de Broglie wavelength corresponding to a ball of mass 100 g moving with a speed of 33 m/s? (Plank's constant-6.6 x10-34 J/s)

Two thin convex lenses L1 and L2,have focal lengths 4 cm and 10 cm, respectively. They are separated by a distance of x cm as shown in the figure. A point source S is placed on the principal axis at a distance 12 cm to the left of L1. If the image of S is formed at infinity, the value of x is:
Consider a particle executing a simple harmonic motion. Let x,A,K and U are displacement,amplitude,kinetic energy and potential energy,respectively,of the particle at certain instant of time. If\(\frac{K}{U}\)=3,then \(\frac{x}{A}\) is:

A car is moving with an initial speed of 5 m/s. A constant braking force is applied and the car is brought to rest in a distance of 10 m. What is the average speed of the car during the deceleration process?

Consider a vector addition \(\vec{P}\)+\(\vec{Q}\)=\(\vec{R}\). If \(\vec{P}\)=|\(\vec{P}\)|\(\hat{i}\),|\(\vec{Q}\)|=10 and\(\vec{R}\)= 3 |\(\vec{P}\)|\(\hat{j}\),then |\(\vec{P}\)| is:

A projectile is thrown at a speed V and at an angle with the horizontal. If the speed at its maximum height is \(\frac{V}{3}\),then the value of tan θ is: