IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: ashwinkandel on October 25, 2010, 12:30:40 pm

Title: physics question related to electricity.
Post by: ashwinkandel on October 25, 2010, 12:30:40 pm
i m confused with one question.  hope someone posts the solution with reasoning. the question is uploaded here::
http://www.mediafire.com/?p02cor3wp44h9hj
Title: Re: physics question related to electricity.
Post by: Chingoo on October 25, 2010, 02:41:20 pm
6(a) Plate Y is positively charged, as weight acts in downward direction and a repulsive force of equal magnitude but opposite direction between the positively charged plate and positive particle causes the particle to be stationary.
6(b)(i) E = V/d (where E = Electric Field Strength, V = Potential Difference, d = Separation between Plates)
                   E = (630)/(0.75 x 10-2)
                   E = 8.4 x 104 NC-1 or Vm-1
6(b)(ii) F = ma (where F = Force Acting on the Particle, m = Mass of the Particle, a = Acceleration due to Gravity)
                   F = (9.6 x 10-15)(9.81)
                   F = 9.418 x 10-14 N ~ 9.42 x 10-14 N
                   E = F/Q (where E = Electric Field Strength, F = Force Acting on the Particle, Q = Charge on the Particle)
                   Q = F/E
                   Q = (9.418 x 10-14)/(8.4 x 104)
                   Q = 1.121 x 10-14 C ~ 1.12 x 10-14 C

Feel free to ask for further explanation ^_^
Title: Re: physics question related to electricity.
Post by: Deadly_king on October 26, 2010, 05:04:23 am
Quote from: Chingoo on October 25, 2010, 02:41:20 pm
6(a) Plate Y is positively charged, as weight acts in downward direction and a repulsive force of equal magnitude but opposite direction between the positively charged plate and positive particle causes the particle to be stationary.
6(b)(i) E = V/d (where E = Electric Field Strength, V = Potential Difference, d = Separation between Plates)
                   E = (630)/(0.75 x 10-2)
                   E = 8.4 x 104 NC-1 or Vm-1
6(b)(ii) F = ma (where F = Force Acting on the Particle, m = Mass of the Particle, a = Acceleration due to Gravity)
                   F = (9.6 x 10-15)(9.81)
                   F = 9.418 x 10-14 N ~ 9.42 x 10-14 N
                   E = F/Q (where E = Electric Field Strength, F = Force Acting on the Particle, Q = Charge on the Particle)
                   Q = F/E
                   Q = (9.418 x 10-14)/(8.4 x 104)
                   Q = 1.121 x 10-14 C ~ 1.12 x 10-14 C

Feel free to ask for further explanation ^_^

Nice piece of work Chingoo :)

Thanks for your help ;)