(a) An experiment was performed in the laboratory in the sequence described I. Brought a positively charged plastic ruler near to the cap of an uncharged...

(a) An experiment was performed in the laboratory in the sequence described
I. Brought a positively charged plastic ruler near to the cap of an uncharged leaf electroscope
II. Touched the cap momentarily with the finger
III. Removed the ruler
Draw diagram to show charge distribution on the cap and leaf of the electroscope and the position of the leaf after each of the above procedure.
(b) What will be the effect observed if the ruler is removed before removing the finger?
(c) In a separate experiment, the charged plastic ruler was allowed to touch the cap of electroscope. State giving a reason whether or not there will be any difference in the results obtained in (a) above
(d) In a nylon manufacturing factory heavy rubber units were put under the spinning machines which were made of metal to absorb the noise. The following effects were observed
A. Workers sometimes received electric shock when there was no leakage of charge from the main cable.
B. Small pieces of nylon stuck to the thread but whenever the room was moist this did not occur
(i) State and explain the reasons for the observation in A and B above.
(ii) How would the effect in (d) A be corrected

Answers

b)The negative charges present on the cap will be conducted to the earth leaving the electroscope with no net charge.
c)The positively charged ruler will leave positive charge on the electroscope. The gold leaf will be positively charged i.e. charging by contact.
d)i) A – When the machines are spinning there is friction between air and nylon; thread and nylon rubber and air. This results into charging the objects which results in electric shock .
B – Nylon pieces have opposite charge to that on the thread hence they attract; moist air conducts away charge on thread and nylon pieces leaving them with no net charge.
ii) Small strips of metal could be connected from the rubber to the ground to conduct the charge away.

Kavungya answered the question on October 3, 2019 at 06:00

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