MCQ
Unit of radioactivity is Rutherford. Its value is
  • A
    $3.7 \times {10^{10}}\,\,disintegrations/sec$
  • B
    $3.7 \times {10^6}\,\,disintegrations/sec$
  • C
    $1.0 \times {10^{10}}\,\,disintegrations/sec$
  • $1.0 \times {10^6}\,\,disintegrations/sec$

Answer

Correct option: D.
$1.0 \times {10^6}\,\,disintegrations/sec$
d
(d)

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

Two circuits have mutual inductance of $0.1\, H$. What average $e.m.f$. is induced in one circuit when the current in the other circuit changes from $0$ to $20\, A$ in $0.02$ $s$......$V$
Finger prints are observed by the use of
Two slits, $4 \,mm$ apart, are illuminated by light of wavelength $6000 Å$. What will be the fringe width on a screen placed $2\,m$ from the slits.....$mm$
Back surface of a glass (refractive index $n$ and thickness $t$ ) is polished to work as a mirror as shown below. A laser beam falls on it and is partially reflected and refracted at the air-glass interface and fully reflected at the mirror surface, respectively. A pattern of discrete spots of light is observed on the screen. The spacing between the spots on the screen will be
Radioactive nuclei $P$ and $Q$ disintegrate into $R$ with half lives 1 month and 2 months respectively. At time $t=$ 0 , number of nuclei of each $P$ and $Q$ is $x$. Time at which rate of disintegration of $P$ and $Q$ are equal, number of nuclei of $R$ is ........ $x$
The current $(i)$ at time $t =0$ and $t =\infty$ respectively for the given circuit is
If $ m$ is magnetic moment and $B$ is the magnetic field, then the torque is given by
When a body is charged by induction, then the body.
The resistivity of a potentiometer wire is $40 \times {10^{ - 8}}\,ohm - m$ and its area of cross-section is $8 \times {10^{ - 6}}\,{m^2}$. If $0.2\, amp$ current is flowing through the wire, the potential gradient will be
In normal adjustment, for a refracting telescope, the distance between objective and eye piece is $30\,cm$. The focal length of the objective, when the angular magnification of the telescope is $2$ , will be $.....cm$