Four identical pendulums are made by attaching a small ball of mass $100 \,g$ on a $20 \,cm$ long thread and suspended from the same point. Now, each ball is given charge $Q$, so that balls move away from each other with each thread making an angle of $45^{\circ}$ from the vertical. The value of $Q$ is close to ..............$\mu C$ $\left(\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9\right.$ in $SI$ units $)$
Four identical pendulums are made by attaching a small ball of mass $100 \,g$ on a $20 \,cm$ long thread and suspended from the same point. Now, each ball is given charge $Q$, so that balls move away from each other with each thread making an angle of $45^{\circ}$ from the vertical. The value of $Q$ is close to ..............$\mu C$ $\left(\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9\right.$ in $SI$ units $)$
- [KVPY 2017]
- A
$1$
- B
$1.5$
- C
$2$
- D
$2.5$
Similar Questions
Two identical conducting spheres $A$ and $B,$ carry equal charge. They are separated by a distance much larger than their diameter, and the force between them is $F$ . A third identical conducting sphere, $C,$ is uncharged. Sphere $C$ is first touched to $A,$ then to $B,$ and then removed. As a result, the force between $A$ and $B$ would be equal to
Two identical conducting spheres $A$ and $B,$ carry equal charge. They are separated by a distance much larger than their diameter, and the force between them is $F$ . A third identical conducting sphere, $C,$ is uncharged. Sphere $C$ is first touched to $A,$ then to $B,$ and then removed. As a result, the force between $A$ and $B$ would be equal to
- [JEE MAIN 2018]
If $g_E$ and $g_M$ are the accelerations due to gravity on the surfaces of the earth and the moon respectively and if Millikan's oil drop experiment could be performed on the two surfaces, one will find the ratio (electronic charge on the moon/electronic charge on the earth) to be
If $g_E$ and $g_M$ are the accelerations due to gravity on the surfaces of the earth and the moon respectively and if Millikan's oil drop experiment could be performed on the two surfaces, one will find the ratio (electronic charge on the moon/electronic charge on the earth) to be
- [AIEEE 2007]
Two spheres $A$ and $B$ of radius $4\,cm$ and $6\,cm$ are given charges of $80\,\mu c$ and $40\,\mu c$ respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is
Two spheres $A$ and $B$ of radius $4\,cm$ and $6\,cm$ are given charges of $80\,\mu c$ and $40\,\mu c$ respectively. If they are connected by a fine wire, the amount of charge flowing from one to the other is
Two spherical conductors $B$ and $C$ having equal radii and carrying equal charges in them repel each other with a force $F$ when kept apart at some distance. A third spherical conductor having same radius as that of $B$ but uncharged is brought in contact with $B$, then brought in contact with $C$ and finally removed away from both. The new force of repulsion between $B$ and $C$ is
Two spherical conductors $B$ and $C$ having equal radii and carrying equal charges in them repel each other with a force $F$ when kept apart at some distance. A third spherical conductor having same radius as that of $B$ but uncharged is brought in contact with $B$, then brought in contact with $C$ and finally removed away from both. The new force of repulsion between $B$ and $C$ is
- [AIEEE 2004]
The value of electric permittivity of free space is
The value of electric permittivity of free space is