NEET2009PhysicsElectrostaticsActual
A charged oil drop is suspended in unifor m field of 3 10^4 ~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 / s ^2 )
Options
- A3.3 10⁻¹⁸ C
- B3.2 10⁻¹⁸ C
- C1.6 10⁻¹⁸ C
- D4.8 10⁻¹⁸ C
Correct answer
A. 3.3 10⁻¹⁸ C
Step-by-step solution
aligned & In steady state, & electric force on drop & aligned & = weight of drop aligned aligned q E= & m g & q= m g E & = 9.9 10⁻¹⁵ 10 3 10^4 & =3.3 10⁻¹⁸ C aligned aligned