Science
Sometimes, a crackling sound is heard while taking off a sweater during winter. Explain.
Answer
The crackling sound heard when removing a sweater in winter is a result of the friction between the woollen fabric and the body or the shirt worn underneath. This friction generates opposite electric charges, and the discharge of these charges produces the audible crackling sound.
Related Questions
When a glass rod is rubbed with a piece of silk cloth, the rod
- and the cloth both acquire a positive charge.
- becomes positively charged while the cloth has a negative charge.
- and the cloth both acquire a negative charge.
- becomes negatively charged while the cloth has a positive charge.
Write T against true and F against false in the following statements.
(a) Like charges attract each other. (T/F)
(b) A charged glass rod attracts a charged plastic straw. (T/F)
(c) Lightning conductors cannot protect a building from lightning. (T/F)
(d) Earthquakes can be predicted in advance. (T/F)
Explain why a charged body loses its charge if we touch it with our hand.
Name the scale on which the destructive energy of an earthquake is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph? Is it likely to cause much damage?