Question
Define the term 'activity' of radionuclide. Write its SI unit.

Answer

The total decay rate of a sample of one or more radionuclide is called activity.Alternate Answer
Radioactive disintegration taking place per second.Alternate Answer
$\text{R} = - \frac{\text{dN}}{\text{dt}} , $where N is the total number of radionuclides at any time ‘t’. SI unit-becquerel(Bq) .
 

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If the intensity of sound is doubled, by how many decibels does the sound level increase?
Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to $(E_g)_C, (E_g)_{si }$and $(E_g)_{Ge}.$ Which of the following statements is true?
Answer the following:
What are the forms of energy into which the electrical energy of the atmosphere is dissipated during a lightning? $($Hint: The earth has an electric field of about $100Vm^{–1}$ at its surface in the downward direction, corresponding to a surface charge density $= –10^{–9}Cm^{–2}$​​​​​​​. Due to the slight conductivity of the atmosphere up to about $50\ km \ ($beyond which it is good conductor$),$ about $+ 1800C$ is pumped every second into the earth as a whole. The earth, however, does not get discharged since thunderstorms and lightning occurring continually all over the globe pump an equal amount of negative charge on the earth.$)$
A converging lens is kept coaxially in contact with a diverging lens – both the lenses being of equal focal lengths. What is the focal length of the combination?
Name the physical quantity whose unit is newton metre tesla ${ }^{-1}$ and whether is it scalar or vector?
Suppose that the lower half of the concave mirror's reflecting surface in Fig. 9.6 is covered with an opaque (non-reflective) material. What effect will this have on the image of an object placed in front of the mirror?
What type of wave front will emerge?
(i) From a point light source, (ii) From a remote light source.
If the intensity of radiation in a photocell is increased how does the stopping potential vary?
Write the relation for the speed of electromagnetic waves in terms of the amplitudes of electric and magnetic fields.
Raindrops of radius $1mm$ and mass $4mg$ are falling with a speed of $30m/s$ on the head of a bald person. The drops splash on the head and come to rest. Assuming equivalently that the drops cover a distance equal to their radii on the head, estimate the force exerted by each drop on the head.