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State Coulomb's law of force between electric charges - Leaving Cert Physics - Question c - 2018
Question c
State Coulomb's law of force between electric charges. The diagram shows a positively-charged electroscope. (i) Give a use for an electroscope. (ii) How can an el... show full transcript
Worked Solution & Example Answer:State Coulomb's law of force between electric charges - Leaving Cert Physics - Question c - 2018
Step 1
State Coulomb's law of force between electric charges.
Answer
Coulomb's law states that the force between two electric charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them. Mathematically, it can be expressed as:
ightarrow rac{Q_1 Q_2}{r^2}$$Step 2
Step 3
(ii) How can an electroscope be given a positive charge?
Answer
An electroscope can be given a positive charge by bringing it into contact with a positively charged object or by bringing it close to a negatively charged object. In the latter case, if the electroscope is connected to the ground, negative charges from the electroscope will move to the earth, leaving the electroscope positively charged.
Step 4
Step 5
(iv) Explain why this happens.
Answer
This happens because touch allows the transfer of charge between the electroscope and your body. Negative charges flow from the earth (your body) into the electroscope, neutralizing its positive charge. As a result, the leaves lose their charge and fall back together.