Anderson Sec Sch 2007 Sec 4 CA1 Q14
The figure below shows a person walking on a carpet and approaching a metal door which is earthed.
(a) It is found that the carpet on which the person has walked on carries positive charges. Explain briefly how these charges are formed.
(b) What kind of electric charges can be found on the body of the person?
(c) When the person is close to the metal door, sketch the distribution of electric charges on the person and the metal door in the following figure.
(d) What happens when the person touches the metal door? Explain briefly.
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Answer:
(a) When the person's shoes rubbed against the carpet, there is friction. Electrons are transferred from the carpet to the person. The person has an excess of electrons and is negative.
(b) Negative.
(c)
(d) The negative charges on the person's body will be discharge through the door, which is earthed. The person will feel a slight and short electric shock.
