Page 1 :
PRACTICE QUESTIONS, , Very Short Answer Type Questions [1 Mark] (i) anice cube of mass 1.5 kg is put into the, 1. Which type of substances are called bucket?, elastomers? Give one example. [NCT 2011] (ii) an iron piece of mass 7.8 kg suspended, 2. Whatare the factors that may affect elasticity by another string is immersed with, of a material? half its volume inside the water in the, 3. Why are springs made of steel and not of bucket (Relative density of iron = 7.8)?, copper? 9. A wire of length / and area of cross4. What does Hooke’s law essentially define ? section A is stretched by the application, , of a force. If the Young’s modulus is, Y, what is the work done per unit volume?, , Short Answer Type Questions [2 Marks], 5. Why is steel more elastic than rubber?, 6. The length of a metal is /, when the tension Numericals ', in it is T, and is /, when the tension is T,. 10. Two wires, one of steel and the other of, , Find the original length of the wire. aluminium, each 2 m long and of diameter, , 7. Explain the terms : Young’s modulus of 2.0 mm, are joined end to end to form a, , elasticity and elastic fatigue. composite wire of length 4.0 m. What tension, , Long Answer Type [I] Questions [3 Marks] in the wire will produce a total extension of, 0.90 mm?, , 8. Aspring balance reads 10 kg when a bucket, of water is suspended from it. What is the Y for steel=2 x 10'! Nm“; Y for aluminium, reading on the spring balance when : = 7x 10!! Nm”.