+91-87964 74404
FlagBACK
Question icon
Grade 12Electrostatics

how many electrons should be added or removed from a neutral body of mass 10 mg so that it May remain stationary in air in an electric field of strength 100 N/C directed upwards (g = 10m/s^2)

Profile image of Dina
9 Years agoGrade 12
Answers icon

4 Answers

Profile image of Vikas TU
9 Years ago
Dear Student,
The given electric field ought to apply an upward constrain on the molecule so it scratchs off the gravitational compel which follows up on the molecule the descending way. 
Since the electric field is coordinated upwards, along these lines the molecule ought to be decidedly charged so an upward compel follows up on it because of the electric field. 
Presently, net drive on the molecule = Fnet = 0 
Taking the upward course as positive, we have: 
Fnet = Fe – Fg = 0 
=> qE – mg = 0 
=> q = mg/E 
Substituting 
E = 4N/C and g = 10m/s2 , we get:
q = 5mC.
Cheers!!
Regards,
Vikas (B. Tech. 4th year
Thapar University)
Profile image of Rahul Kumar Bastia
7 Years ago
Fnet=Fe- mg
=>Fe = mg. Again, Fe = qE = neE
=>neE = mg
=>n = mg/eE
Given E = 100 N/C , m= 10×10–3 = 10–2 kg and g=10 m/ s²
=>n = 10–2×10/1.6 ×10–19×100
=> n = 6.25 × 10^15 electrons
As the E is in upward direction hence electrons must be removed to make it stable.
Profile image of Vikhyat
7 Years ago
 
Fnet=Fe- mg
=>Fe = mg. Again, Fe = qE = neE
=>neE = mg
=>n = mg/eE
Given E = 100 N/C , m= 10×10–3 = 10–6 kg and g=10 m/ s²
=>n = (10–6×10) ÷(1.6 ×10–19×100)
=> n = 6.25 × 10^12 electrons
As the E is in upward direction hence electrons must be removed to make it stable.
Profile image of Kiran Pawar
7 Years ago
Dear students here n is asked so one simple formula is 
Charge = no.× ectron 
Charge/electron =no
And as know Fe = mg 
                        Ee= mg 
                      E×e/charge = mg 
Just put the value and get answers by your own ....
 

Other Related Questions on electrostatics

question mark
Electrostatics question based on earthing of spherical shell
electrostatics
1 Answer Available

Last Activity: 3 Years ago

question mark
an object has a charge of 2c and gains 10^19 electrons. the net chaarge on the object becomes??
electrostatics
1 Answer Available

Last Activity: 4 Years ago

question mark
A wire with a linear charge density lambda forms a quarter of a cjrclenof radius R and is placed asa shown in thefigure with its centre of curvature at the origin O the electric field at O will be
electrostatics
1 Answer Available

Last Activity: 4 Years ago

question mark
Find the value of q so that system remains in equilibrium.. figure attached below
electrostatics
1 Answer Available

Last Activity: 4 Years ago

question mark
Need to find the time taken for the dipole to come back to eqm
 
electrostatics
1 Answer Available

Last Activity: 4 Years ago