1. Tardigrade
  2. Question
  3. Physics
  4. A charged particle q is shot towards another charged particle Q (which is fixed) with a speed v . It approaches Q up to the closest distance r and then returns. If q were given a speed 2v , the closest distance of approach would be <img class=img-fluid question-image alt=Question src=https://cdn.tardigrade.in/q/nta/p-eemizujyuw4ej5ft.jpg />

Q. A charged particle $q$ is shot towards another charged particle $Q$ (which is fixed) with a speed $v$ . It approaches $Q$ up to the closest distance $r$ and then returns. If $q$ were given a speed $2v$ , the closest distance of approach would be
Question

NTA AbhyasNTA Abhyas 2022 Report Error

Solution:

From conservation of mechanical energy
$\frac{1}{2}mv^{2}=\frac{k q Q}{r}$
In second case
$\frac{1}{2}m\left(\right.2v \left(\left.\right)^{2}=\frac{k q Q}{r^{′}}$
$r^{′}=\frac{r}{4}$

Questions from NTA Abhyas 2022

1. A thin semicircular conducting ring of the radius $R$ is falling with its plane vertical in a horizontal magnetic induction $\overset{ \rightarrow }{B}$ . At the position MNQ, the speed of the ring is $v$ and the potential difference developed across the ring is
Question

2. An ideal gas at $27 \, ^\circ C$ is compressed adiabatically to $8/27$ of its original volume. If $\gamma =5/3$ , then the rise in temperature is

3. Two bullets are fired simultaneously, horizontally and with different speeds from the same place. Which bullet will hit the ground first?

4. Two perfectly elastic objects $A$ and $B$ of identical mass are moving with velocities $15 \, m \, s^{- 1}$ and $10 \, m \, s^{- 1}$ respectively, collide along the direction of line joining them. Their velocities after the collision are respectively

5. The force of repulsion between two point charges is $F$ , when these are at distance $0.5 \, m$ apart. Now the point charges are replaced by non conducting spheres of radii $5 \, cm$ each having the same charge as that of the respective point charges. The distance between their centres is again kept $0.5m.$ Then the force of repulsion will

Electrostatic Potential and Capacitance

Physics Most Viewed Questions

1. If $E$ and $G$ respectively denote energy and gravitational constant, then $\frac{ E }{ G }$ has the dimensions of:

NEET 2021 Physical World, Units and Measurements

2. The de Broglie wavelength of an electron moving with kinetic energy of $144 \,eV$ is nearly

NEET 2020 Dual Nature of Radiation and Matter

3. A car starts from rest and accelerates at $5\, m / s ^{2}$ At $t=4\, s$, a ball is dropped out of a window by a person sitting in the car. What is the velocity and acceleration of the ball at $t =6\, s$ ? (Take $\left. g =10\, m / s ^{2}\right)$

NEET 2021 Motion in a Straight Line

4. A wheel with $20$ metallic spokes each $1\, m$ long is rotated with a speed of $120\, rpm$ in a plane perpendicular to a magnetic field of $0.4\, G$. The induced emf between the axle and rim of the wheel will be, $(1 G = 10^{-4}\, T)$

NEET 2020 Electromagnetic Induction

5. A barometer is constructed using a liquid (density $= 760 \,kg/m^{3})$ What would be the height of the liquid column, when a mercury barometer reads $76\, cm$ ?
(density of mercury $= 13600 kg/m^{3})$

NEET 2020 Mechanical Properties of Fluids

Latest Updates