Download App

The Nucleus — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsThe Nucleus1 Mark
Question
In one average-life:
  1. Half the active nuclei decay.
  2. Less than half the active nuclei decay.
  3. More than half the active nuclei decay.
  4. All the nuclei decay.
✓

Answer

  1. More than half the active nuclei decay.

Explanation:

The average life is the mean life time for a nuclei to decay.

It is given as

$\tau=\frac{1}{\lambda}=\frac{\text{T}_{\frac{1}{2}}}{0.693}$

Here, $\tau,\lambda$ and $\text{T}_{\frac{1}{2}}$ are the average life, decay constant and half life-time of the active nuclei, respectively. The value of the average lifetime comes to be more than the average lifetime. Therefore, in one average life, more than half the active nuclei decay.

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

Explore more

More "M.C.Q [1M]" from The Nucleus→The Nucleus — all question types→Physics STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

When the intensity of a light source is increased:
  1. The number of photons emitted by the source in unit time increases.
  2. The total energy of the photons emitted per unit time increases.
  3. More energetic photons are emitted.
  4. Faster photons are emitted.
→
Forbidden gap in a pure conductor is:
→

Bragg’s law for X-rays is

(a) d sin θ = 2n λ

(b) 2dsin θ = n λ

(c) n sin θ = 2 λ d

(d) None of these
→

Match the List I with the List II from the combinations shown

(I)

Presbiopia

(A)

Sphero-cylindrical lens

(II)

Hypermetropia

(B)

Convex lens of proper power may be used close to the eye

(III)

Astigmatism

(C)

Concave lens of suitable focal length

(IV)

Myopia

(D)

Bifocal lens of suitable focal length

(a) I-A; II-C; III-B; IV-D

(b) I-B; II-D; III-C; IV-A

(c) I-D; II-B; III-A; IV-C

(d) I-D; II-A; III-C; IV-B
→

The pole pieces of the magnet used in a pivoted coil galvanometer are

(a) Plane surfaces of a bar magnet

(b) Plane surfaces of a horse-shoe magnet

(c) Cylindrical surfaces of a bar magnet

(d) Cylindrical surfaces of a horse-shoe magnet
→
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 $\left(E_g\right)_C,\left(E_g\right)_{S i}$ and $\left(E_g\right)_{G e}$. Which of the following statements is true?
→

Doping of intrinsic semiconductor is done

(a) To neutralize charge carriers

(b) To increase the concentration of majority charge carriers

(c) To make it neutral before disposal

(d) To carry out further purification
→
Heat and work are equivalent. This means:
  1. When we supply heat to a body we do work on it.
  2. When we do work on a body we supply heat to it.
  3. The temperature of a body can be increased by doing work on it.
  4. A body kept at rest may be set into motion along a line by supplying heat to it.
→
The solar spectrums is :
→

The hottest planet of solar system is

(a) Mars 

(b) Mercury

(c) Venus

(d) Pluto
→