NEET (UG) entrance exam Question Bank Solutions

An intrinsic semiconductor has a resistivity of 0.50 Ω m at room temperature. Find the intrinsic carrier concentration if the mobilities of electrons and holes are 0.39 m²V^-1S^-1 and O.11 m² v^-1S^-1 respectively:

Root mean square velocity of a particle is V at pressure P. If pressure is increased two times, then the rms velocity becomes ______.

If a body is moving in a circle of radius r with a constant speed v, its angular velocity is ______.

If the net external force acting on the system of particles is zero, then which of the following may vary?

The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the root mean square speed of gas molecules is V, then at 480, it will be ______.

The equation of a simple harmonic progressive wave is given by y = A sin (100πt − 3x). Find the distance between 2 particles having a phase difference of `π/3`.

Taking into account of the significant figures, what is the value of 9.99 m – 0.0099 m?

A uniform rectangular block of mass of 50 kg is hung horizontally with the help of three wires A, B and C each of length and area of 2m and 10mm² respectively as shown in the figure. The central wire is passing through the centre of gravity and is made of material of Young's modulus 7.5 x 10¹⁰ Nm⁻² and the other two wires A and C symmetrically placed on either side of the wire B are of Young's modulus 10¹¹ Nm⁻²  The tension in the wires A and B will be in the ratio of: 

The maximum and minimum tensions in the string whirling in a circle of radius 2.5 m with constant velocity are in the ratio 5 : 3. Then its velocity is

Light waves travel from optically rarer medium to optically denser medium. Its velocity decreases bec;ause of change in ______.

To study the helical surface of nucleic acid, the property of electromagnetic radiation generally used is ______.

Lenard observed photoelectric effect using

When a bus suddenly takes a tum, the passengers are thrown outwards because of

Force acting on a particle moving in a straight line varies with the velocity of the particle v as F = `K/v`, where K is a constant. The work done by this force in time t is

The kinetic energy of a body of mass 4 kg and momentum 6 Ns will be

Two identical spheres of mass ' m' are placed at the two vertices of an equilateral triangle. A sphere of mass ' 2 m' is placed at the third vertex. The centre of mass of the whole system will be at [Each side of the triangle is 8 cm]

Broadcasting antennas are generally ______.

What is the shape assumed by the surface when a non-wetting liquid is placed in a capillary tube? 

The force of attraction between two unit point masses separated by a unit distance is numerically equal to

Two particles P and Q describe simple harmonic motions of same amplitude a, frequency v along the same straight line. The maximum distance between the two particles is a`sqrt(2)`. The initial phase difference between the particles is