MCQ
An electron having charge ‘$e$’ and mass ‘$m$’ is moving in a uniform electric field $E$. Its acceleration will be
- A$\frac{{{e^2}}}{m}$
- B$\frac{{{E^2}e}}{m}$
- ✓$\frac{{eE}}{m}$
- D$\frac{{mE}}{e}$
✓
Answer
Correct option: C.
$\frac{{eE}}{m}$
c
$a = \frac{F}{m} = \frac{{eE}}{m}$
$a = \frac{F}{m} = \frac{{eE}}{m}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The radius of hydrogen atom in its ground state is $5.3 \times {10^{ - 11}}m$. After collision with an electron it is found to have a radius of $21.2 \times {10^{ - 11}}m$. What is the principal quantum number $n$ of the final state of the atom $n=.........$
→A parallel plate capacitor of capacitance $12.5 \mathrm{pF}$ is charged by a battery connected between its plates to potential difference of $12.0 \mathrm{~V}$. The battery is now disconnected and a dielectric slab $\left(\in_{\mathrm{r}}=6\right)$ is inserted between the plates. The change in its potential energy after inserting the dielectric slab is_______.$\times 10^{-12} \mathrm{~J}$.
→A glass beaker has a solid, plano-convex base of refractive index $1.60$ , as shown in the figure. The radius of curvature of the convex surface ($SPU$) is $9 cm$, while the planar surface ($STU$) acts as a mirror. This beaker is filled with a liquid of refractive index $n$ up to the level $QPR$. If the image of a point object $O$ at a height of $h$ (OT in the figure) is formed onto itself, then, which of the following option($s$) is (are) correct?
→$(A)$ For $n=1.42, h=50 \ cm$ $(B)$ For $n=1.35, h=36 \ cm$ $(C)$ For $n=1.45, h=65 \ cm$ $(D)$ For $n=1.48, h=85 \ cm$
The field due to a long straight wire carrying a current I is proportional to
The photodiode is used to detect the optiocal signals. These diodes are preferably operated in reverse biased mode because.
Two charges each equal to $\eta q({\eta ^{ - 1}} < \sqrt 3 )$ are placed at the corners of an equilateral triangle of side $a$. The electric field at the third corner is ${E_3}$ where $({E_0} = q/4\pi {\varepsilon _0}{a^2})$
→A uniform wire of resistance $R$ is uniformly compressed along its length, until its radius becomes $n$ times the original radius. Now resistance of the wire becomes
→An achromatic telescope objective is to be made by combining the lenses of flint and crown glasses. This proper choice is
If $I _0$ is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled
→Radiations of monochromatic waves of wavelength $400\ nm$ are incident on the surface of metals $Zn$, $Fe$ and $Ni$ of work functions $3.4\ eV$, $4.8\ eV$ and $5.9\ eV$ respectively. (Take $hc = 1242\ eV\ nm$)
→$(a)$ Maximum $KE$ associated with photoelectrons from the surface of any metal is $0.3\ eV$
$(b)$ No photoelectrons are emitted from the surface of $Ni$
$(c)$ If the frequency of the source of radiation is doubled then $KE$ of photoelectrons is also doubled
$(d)$ Photoelectrons will be emitted from the surfaces of all the three metals if the wavelength of the incident radiation is less than $200\ nm$
Correct statements are