The maximum number of electrons possible in subshell is equal to
How many electrons with / = 2 are there in an atom having atomic number 54?
Out of X-rays, infrared rays, visible rays and microwaves, the largest frequency is of
If 250J of work is done in sliding a5 kg block up an inclined plane of height 4 m. Work done against friction is (g = 10 ms–2)
KE acquired by a mass m in travelling a certain distance d, starting from rest, under the action of a constant force F is
The power of water pump is 4 kW. If g = 10 ms–2, the amount of water it can raise in 1 minute to a height of 20 m is
A U–238 nucleus originally at rest, decays by emitting an alpha-particle, say with a velocity of v m/s. The recoil velocity (in ms–1) of the residual nucleus is
A bullet weighing 10 g and moving with a velocity 800 ms–1 strikes a 10 kg block resting on a frictionless surface. The speed of the block after the perfectly inelastic collision is approximately
When momentum of a body increases by 200%, its KE increases by
A drop of mass 2.0 g falls from a cliff of height 1.0 km. It hits the ground with a speed of 50.0 ms–1. The work done by the resistive force is
Two bodies of masses m1 and m2 have same kinetic energy. The ratio of their momentum is
Under the action of a force, a 1 kg body moves, such that its position x as a function of time t is given by x= t*t*t / 2,where x is in meter and t is in second.The work done by the force in first 3 second is
A string is used to pull a block of mass m vertically up by a distance h at a constant acceleration 3 . The work done by the tension in the string is
In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be
In a common base amplifier, the phase difference between the input signal voltage and output voltage is
The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 nm is incident on it. The band gap in (eV) for the semiconductor is
The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than 2480 nm is incident on it. The band gap in (eV) for the semiconductor is
When p-n junction diode is forward biased, then
The manifestation of band structure in solids is due to
A piece of copper and another of germanium are cooled from room temperature to 77 K, the resistance of
For a transistor amplifier in common emitter configuration for load impedance of 1 
the current gain is
When npn transistor is used as an amplifier
In the middle of the depletion layer of a reverse biased p-n junction, the
The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the
A strip of copper and another germanium are cooled from room temperature to 80 K. The resistance of
Formation of covalent bonds in compounds exhibits
Which part of a transistor is most heavily doped to produce large number of majority carriers?
The energy band gap is maximum in
By increasing the temperature, the specific resistance of a conductor and a semiconductor
At absolute zero, Si acts as
The period of revolution of a satellite orbiting Earth at a height 4R above the surface of Earth is x hrs, where R is the radius of earth. The period of another satellite at a height 1.5R from the surface of the Earth is
The value of acceleration due to gravity will be 1% of its value at the surface of earth at a height of (Re = 6400 km)
If the radius of earth shrinks to kR (k < 1), where R is the radius of Earth, then the time period of rotation of Earth, about its axis will become
A thin uniform annular disc (see figure) of mass M has outer radius 4R and inner radius 3R. The work required to take a unit mass from point P on its axis to infinity is
A planet of radius R = 1/10 (radius of Earth) has the same mass density as Earth. Scientists dig a well of 10 depth R5 on it and lower a wire of the same length and of linear mass density 10–3 kg m–1 into it. If the wire is not touching anywhere, the force applied at the top of the wire by a person holding it in place is (take the radius of Earth = 6 × 106 m and the acceleration due to gravity on Earth is 10 ms–2)
A satellite is moving with a constant speed V in a circular orbit about the earth. An object of mass m is ejected from the satellite such that it just escapes from the gravitational pull of the earth. At the time of its ejection, the kinetic energy of the object is
The ratio between masses of two planets is 3 : 5 and the ratio between their radii is 5 : 3. The ratio between their acceleration due to gravity will be
If the radius of earth were to shrink by one percent and mass remains same, then acceleration due to gravity on the surface of the earth would
A planet is at R distance from sun and its time period of revolution is T. What will be its new time period of revolution if it is brought 0.5 R distance closer to sun?
The time period of a satellite of the earth is 10 hours. If the separation between the earth and the satellite is increased to 4 times the previous value, then what will be the new time period of the satellite?
Which of the following layering pattern will have a void fraction of 0.26?
Lithium crystallizes in a body centred cubic lattice, how many next nearest neighbours does each Li has?
Quartz on strong heating followed by rapid cooling gives glass which is an amorphous solid because
F-centers are related to
Zinc sulphide exists in two different structural forms as zinc blende (FCC) and Wurtzite (HCP). What will be the coordination number of cation and anion in both the structures?
Density of crystal decreases in
A tetrahedral void in fcc is formed by atoms at
In a crystalline solid, anion B are arranged in cubic close packing and cation A are equally distributed between octahedral and tetrahedral voids. If all the octahedral voids are occupied, the formula for the solid is
An element (At. mass = 50 g/mol) having fcc structure has unit cell edge length 400 pm. The density of element is
In Zinc blende structure, Zn+2 ions are present in alternate tetrahedral voids and S–2 in ccp. The coordination number of Zn+2 and S–2 are respectively