ElectrostaticsHard
Question
A charged oil drop is suspended in a uniform field of 3 × 104 V/m so that it neither falls nor rises. The charge on the drop will be (take the mass of the charge = 9.9 × 10-15 kg and g = 10 m/s2)
Options
A.3.3 × 10-18C
B.3.2 × 10-18C
C.1.6 × 10-18C
D.4.8 × 10-18C
Solution
Since ball is hanging in equilibrium, force by gravity is balanced by electric force.
qE = mg
⇒
⇒
∴ q = 3.3 × 10-18C
qE = mg
⇒

⇒
∴ q = 3.3 × 10-18C
Create a free account to view solution
View Solution FreeMore Electrostatics Questions
Three small identical bubbles of water having same charge on each coalesce to form a bigger bubble. Then the ratio of th...A nonconducting solid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at ...Two small identical spheres, each of mass 1 g and carrying same charge 10-9 C are suspended by threads of equal length. ...Two similar spheres having +q and -q charges are kept at a certain distance. F force acts between the two. If in the mid...The total flux associated with given cube will be - where ′a′ is side of cube : - ( = 4π × 9 ×...