An -particle after passing through a potential difference of V vo… - Vidyadip

MCQ

An $\alpha$-particle after passing through a potential difference of $V$ volts collides with a nucleus. If the atomic number of the nucleus is $Z$, then the distance of closest approach of $\alpha$-particle to the nucleus will be

✓
$14.4 \frac{Z}{V} Å$
B
$14.4 \frac{ Z }{ V } m$
C
$14.4 \frac{ Z }{ V } cm$
D
$1.44 \times 10^{-15} m$

✓

Answer

Correct option: A.

$14.4 \frac{Z}{V} Å$

(A) $14.4 \frac{Z}{V} Å$
For closest approach, Initial kinetic energy of $\alpha$-particle = Potential energy of $\alpha$-particle at closest approach
$
\begin{array}{l}
(2 e) V=\frac{1}{4 \pi \varepsilon_0} \frac{(2 e)(Ze)}{d} \\
d=\frac{1}{4 \pi \varepsilon_0} \frac{Ze}{V}=\left(9 \times 10^9\right) \frac{Z}{V}\left(1.6 \times 10^{-19}\right)=14.4 \frac{Z}{V} Å
\end{array}
$

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 "SECTION - A [PHYSICS - MCQ]" from Model Paper 2→Model Paper 2 — all question types→NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Hard $X-$ rays for the study of fractures in bones should have a minimum wavelength of $10^{11}\, m$. The accelerating voltage for electrons in $X-$ ray machine should be

Magnetic flux (in weber) in a closed circuit of resistance $20\,\Omega$ varies with time $t(s)$ as $\phi=8 t ^{2}-9 t +5$. The magnitude of the induced current at $t =0.25\,s$ will be $...mA$

A galvanometer together with an unknown resistance in series is connected to two identical batteries each of $1.5\, V$. When the batteries are connected in series, the galvanometer records a current of $1\,A$, and when batteries are in parallel the current is $0.6\,A$. What is the internal resistance of the battery ?

The planes of two rigid discs are perpendicular to each other. They are rotating about their axes. If their angular velocities are $3 \,rad/sec$ and $4\, rad/sec$ respectively, then the resultant angular velocity of the system would be ........ $rad/sec$

Hubble's law states that the velocity with which the 'milky way' is moving away from the earth is proportional to

If error in measuring diameter of a circle is $4\%$, the error in circumference of the circle would be

A diverging beam of light from a point source $S $ having divergence angle $\alpha$, falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is $t $ and the refractive index $n$, then the divergence angle of the emergent beam is

Following is the relation between current and charge $I = A{T^2}{e^{qt/{V_L}}}$ then value of $VL$ will be

$Assertion$ : The earth is slowing down and as a result the moon is coming nearer to it.
$Reason$ : The angular momentum of the earth moon system is not conserved

The incorrect statement regarding the lines of force of the magnetic field $B$ is