A mass $m = 20\,g$ has a charge $q = 3.0\,mC$. It moves with a velocity of $20\,m/s$ and enters a region of electric field of $80\,N/C$ in the same direction as the velocity of the mass. The velocity of the mass after $3$ seconds in this region is.......$m/s$
$80$
$56$
$44$
$40$
A positively charged particle moving along $x$-axis with a certain velocity enters a uniform electric field directed along positive $y$-axis. Its
A proton and an $\alpha$-particle having equal kinetic energy are projected in a uniform transverse electric field as shown in figure
An electron falls through a distance of $1.5\, cm$ in a uniform electric field of magnitude $2.0\times10^4\, N/C$ as shown in the figure. The time taken by electron to fall through this distance is ($m_e = 9.1\times10^{-31}\,kg$, Neglect gravity)
A particle of mass $1\ gm$ and charge $ - 0.1\,\mu C$ is projected from ground with a velocity $10\sqrt 2 $ at an $45^o$ with horizontal in the area having uniform electric field $1\ kV/cm$ in horizontal direction. Acceleration due to gravity is $10\ m/s^2$ in vertical downward direction. Select $INCORRECT$ statement
An electron falls through a distance of $1.5\; cm$ in a uniform electric field of magnitude $2.0 \times 10^{4} \;N C ^{-1} \text {[Figure (a)]} .$ The direction of the field is reversed keeping its magnitude unchanged and a proton falls through the same distance [Figure $(b)] .$ Compute the time of fall in each case. Contrast the situation with that of 'free fall under gravity'.