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General
Easy
Question
A radioactive material of half-life T was produced in a nuclear reactor at different instants, the quantity produced second time was twice of that produced first time. If now their present activities are A1 and A2 respectively then their age difference equals:
The correct answer is:
Related Questions to study
Physics-
The “
” X-rays emission line of tungsten occurs at l = 0.021 nm. The energy difference between K and L levels in this atom is about
The “” X-rays emission line of tungsten occurs at l = 0.021 nm. The energy difference between K and L levels in this atom is about
Physics-General
physics-
In a characteristic X– ray spectra of some atom superimposed on continuous X– ray spectra:
In a characteristic X– ray spectra of some atom superimposed on continuous X– ray spectra:
physics-General
Physics-
When a hydrogen atom, initially at rest emits, a photon resulting in transition n = 
= 1, its recoil speed is about
When a hydrogen atom, initially at rest emits, a photon resulting in transition n = = 1, its recoil speed is about
Physics-General
Physics-
Electron in a hydrogen atom is replaced by an identically charged particle muon with mass 207 times that of electron. Now the radius of K shell will be
Electron in a hydrogen atom is replaced by an identically charged particle muon with mass 207 times that of electron. Now the radius of K shell will be
Physics-General
physics-
Consider the following electronic energy level diagram of H-atom: Photons associated with shortest and longest wavelengths would be emitted from the atom by the transitions labelled:
Consider the following electronic energy level diagram of H-atom: Photons associated with shortest and longest wavelengths would be emitted from the atom by the transitions labelled:
physics-General
Physics-
In a photoelectric experiment, electrons are ejected from metals X and Y by light of intensity I and frequency f. The potential difference V required to stop the electrons is measured for various frequencies. If Y has a greater work function than X; which one of the following graphs best illustrates the expected results?
In a photoelectric experiment, electrons are ejected from metals X and Y by light of intensity I and frequency f. The potential difference V required to stop the electrons is measured for various frequencies. If Y has a greater work function than X; which one of the following graphs best illustrates the expected results?
Physics-General
physics-
In a photoelectric experiment, the potential difference V that must be maintained between the illuminated surface and the collector so as just to prevent any electron from reaching the collector is determined for different frequencies f of the incident illumination. The graph obtained is shown. The maximum kinetic energy of the electrons emitted at frequency f1 is
In a photoelectric experiment, the potential difference V that must be maintained between the illuminated surface and the collector so as just to prevent any electron from reaching the collector is determined for different frequencies f of the incident illumination. The graph obtained is shown. The maximum kinetic energy of the electrons emitted at frequency f1 is
physics-General
Maths-
then I equals
then I equals
Maths-General
Maths-
dx is equal to
dx is equal to
Maths-General
Maths-
then A+B+C is equal to
then A+B+C is equal to
Maths-General
Physics-
A body of mass 10 kg is moving with a constant velocity of 10 m/s. When a constant force acts for 4 seconds on it, it moves with a velocity 2 m/sec in the opposite direction. The acceleration produced in it is :
A body of mass 10 kg is moving with a constant velocity of 10 m/s. When a constant force acts for 4 seconds on it, it moves with a velocity 2 m/sec in the opposite direction. The acceleration produced in it is :
Physics-General
physics-
A particle moves along the sides AB, BC, CD of a square of side 25m with a velocity of 15 ms–1 Its average velocity is :
A particle moves along the sides AB, BC, CD of a square of side 25m with a velocity of 15 ms–1 Its average velocity is :
physics-General
physics-
Acceleration–time graph of a body is shown. The corresponding velocity–time graph of the same body is :
Acceleration–time graph of a body is shown. The corresponding velocity–time graph of the same body is :
physics-General
physics-
The graph of displacement u/s time is,
Its corresponding velocity–time graph will be :
The graph of displacement u/s time is,
Its corresponding velocity–time graph will be :
physics-General
physics-
Figure (i) and (ii) below show the displacement–time graphs of two particles moving along the x–axis. We can say that :
i) 
ii) 
Figure (i) and (ii) below show the displacement–time graphs of two particles moving along the x–axis. We can say that :
i)
ii)
physics-General
