26 November 2011

8th physics Some Natural Phenomena Assignments

Q1. What type of electric charge is acquired by a rubber balloon when rubbed with a woolen cloth?

Q2. A positively charged object repels another charged object kept close to it. What is the nature of charge on the other object?

Q3. A glass rod is rubbed with a silk cloth & a rubber balloon is rubbed with a woolen cloth.
a) Which two objects acquire negative charge? b) Which two objects acquire positive charge?

Q4. Explain why, a glass rod can be charged by rubbing when held by hand but an iron rod cannot be charged by rubbing, if held by hand?
Q5. Consider three charged bodies P, Q & R. If P & Q repel each other & P attracts R. What is the nature of force between Q & R?
Q6. Name the device used to detect electric charge on a body. Draw its labeled diagram.

Q7. What will you observe when the metal cap of an electroscope is touched with a glass rod which has been rubbed with silk cloth? Give reason for your answer.
Q8. What are the uses of an electroscope? (3 points)
Q9. Why do the leaves of a gold leaf electroscope diverge when a charged body is brought in contact with its disc?
Q10. Do the leaves of an electroscope always diverge to the same extent when a charged body is brought in contact with its disc?
Q11. What will you observe when the metal cap of an electroscope is touched with:
a) A positively charged object?
b) A negatively charged object?
Q12. What happens to the charge on an electroscope when its disc is connected to that of an uncharged electroscope with the help of a conducting wire? What happens to the leaves of the two electroscopes?
Q13. What would you expect in the following cases?
a) A glass rod rubbed with a piece of silk is brought near a negatively charged paper cylinder.
b) A negatively charged body is brought in contact with the disc of a positively charged electroscope.
c) Someone touches the disc of a negatively charged electroscope.
Q14. What will be the charge  
a) on the metal cap
b) on the leaves of an electroscope, if you bring a positive rod near the end of its metal cap.
Q15. What will be the charge
a) on the metal cap &
b) on the leaves of an electroscope, if you bring a positive rod in contact with its metal cap.
Q16. Explain why a charged body loses its charge when we touch it with our hand.

No comments:

Post a Comment

Add and comment