Question 3
Which of the following statements are correct?
(i) Sound is produced by vibrations.
(ii) Sound requires a medium for propagation.
(iii) Light and sound both require a medium for propagation.
(iv) Sound travels slower than light.

(a) i, ii and iv only
(b) i and ii only
(c) i, ii and iii only
(d) ii, iii and iv only

Q. Question 3
Which of the following statements are correct?
(i) Sound is produced by vibrations.
(ii) Sound requires a medium for propagation.
(iii) Light and sound both require a medium for propagation.
(iv) Sound travels slower than light.

(a) i, ii and iv only
(b) i and ii only
(c) i, ii and iii only
(d) ii, iii and iv only

Q.

Which of the following cannot be classified as matter?​
(I) Joy ​
(II) Water bottle ​
(III) Lemonade ​
(IV) Jealousy ​

A. Only I​
B. Only III​
C. Both II and III​
D. Both I and IV​

Q.

Which of the following process / processes release heat ?
(i) condensation (ii) vaporisation (iii) freezing (iv) melting

(a) only (i) (b) only (iv) (c) (i) and (iii) (d) (ii) and (iv)

Q. Which of the following can sometimes be 'zero' for a moving body?

(i) average velocity
(a) only (i)

(ii) distance travelled
(b) (i) and (ii)

(iii) average speed
(c) (i) and (iv)

(iv) displacement
(d) only (iv)

Q.

Which among the following statements are true for unisexual flowers ?
(i) They possess both stamen and pistil
(ii) They possess either stamen or pistil
(iii) They exhibit cross-pollination
(iv) Unisexual flowers possessing only stamens cannot produce fruits

(a) (i) and (iv)
(b) (ii) (iii) and (iv)
(c) (ii) and (iii)
(d) (i), (iii) and (iv)