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.......$m/s$

The electric field inside a spherical shell of uniform surface charge density is

Two identical positive charges are fixed on the $y$ -axis, at equal distances from the  origin $O$. A particle with a negative charge starts on the $x$ -axis at a large distance  from $O$, moves along the $+ x$ -axis, passes through $O$ and moves far away from $O$. Its acceleration $a$ is taken as positive in the positive $x$ -direction. The particle’s  acceleration a is plotted against its $x$ -coordinate. Which of the following best represents  the plot?

A positive charge particle of $100 \,mg$ is thrown in opposite direction to a uniform electric field of strength $1 \times 10^{5} \,NC ^{-1}$. If the charge on the particle is $40 \,\mu C$ and the initial velocity is $200 \,ms ^{-1}$, how much distance (in $m$) it will travel before coming to the rest momentarily

A stream of a positively charged particles having $\frac{ q }{ m }=2 \times 10^{11} \frac{ C }{ kg }$ and velocity $\overrightarrow{ v }_0=3 \times 10^7 \hat{ i ~ m} / s$ is deflected by an electric field $1.8 \hat{ j } kV / m$. The electric field exists in a region of $10 cm$ along $x$ direction. Due to the electric field, the deflection of the charge particles in the $y$ direction is $...........mm$

A toy car with charge $q$ moves on a frictionless horizontal plane surface under the influence of a uniform electric field $\vec E .$ Due to the force $q\vec E$ , its velocity increases from $0$ to $6\,\, m s^{-1}$ in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and tlie average speed of the toy car between $0$ to $3$ seconds are respectively