Improvement in Food Resources — Science STD 9 — Question

The velocities of sound waves in four media P. Q, R and S are 18,000km/h, 900km/h, 0km/h, and 1200km/h respectively. Which medium could be a liquid substance?

1. P
2. Q
3. R
4. S

Amphioxus belongs to:

1. Craniata.
2. Hemochordata.
3. Urochordata.
4. Cephalochordata.

Which one of the following is most likely not a case of uniform circular motion?

Flowering in plants is dependent on:

 A change in the physical state can be brought about:

A linear momentum of a body can be changed by:

The living substance of cell was named by Dujardin as __________.

Which of the following statements are true for pure substances?

1. Pure substances contain only one kind of particles.
2. Pure substances may be compounds or mixtures.
3. Pure substances have the same composition throughout.
4. Pure substances can be exemplified by all elements other than nickel.

1. (i) and (ii)
2. (i) and (iii)
3. (iii) and (iv)
4. (ii) and (iii)

Which of the following are features of Rutherford nuclear model of an atom:

When the amplitude is small, the sound produced is ......: