User Forum

A body goes from point X to point Y with a speed of 10 m s^-1. It comes back to X with a speed of 20 m s^-1. The average speed of the body during the journey is ______.
(a) 15 m s^-1
(b) 16.6 m s^-1
(c) 13.3 m s^-1
(d) 30 m s^-1

(A) 2, 9, 1, 6

(B) 1, 6, 3, 4

(C) 4, 18, 2, 12

(D) 2, 17, 1, 7

Which of the following is an incorrect match?

(A) Alexander Fleming - Penicillin

(B) Louis Pasteur - Fermentation

(C) Edward Jenner - Vaccination

(A) (a) & (b)

(B) (b) & (c)

(C) (a) & (c)

(D) (a), (b) & (c)

In terrestrial plants, roots normally play a very important role in the absorption of nutrients and water from the soil. However, in aquatic plants, roots are much reduced in size. Some of these plants have narrow and thin ribbon-like leaves. These can bend in the flowing water. In some submerged plants, leaves are often highly divided.
Why are their leaves ribbon-shaped or divided ?
(a) The water can easily pass through these leaves without damaging them.
(b) They do not need to store water.
(c) They keep the plant afloat.
(d) They look pretty.

In terrestrial plants, roots normally play a very important role in the absorption of nutrients and water from the soil. However, in aquatic plants, roots are much reduced in size. Some of these plants have narrow and thin ribbon-like leaves. These can bend in the flowing water. In some submerged plants, leaves are often highly divided.
Why do aquatic plants have a root system which is not very well developed?
(a) So that they can be pulled out easily.
(b) It helps them float.
(c) Since they grow in water they don't need long roots to absorb water.
(d) They do not need to absorb minerals.

In the given flow chart,

Pick the incorrect match.
(i) ----- (ii) ----- (iii) ----- (iv)----- (v)
(a) Chemical ----- Physical ----- Chemical ----- Irreversible ----- Reversible
(b) Physical ----- Physical ----- Chemical ----- Chemical ----- Chemical
(c) Irreversible ----- Chemical ----- Physical ----- Reversible ----- Chemical
(d) Irreversible ----- Chemical ----- Chemical ----- Irreversible ----- Irreversible

Which of the following option best shows the front view of the given figure?

(a)
(b)
(c)
(d)

What happens when the North poles of two magnets are held near each other ?

(A) One jumps on to the other

(B) They repel each other

(C) They attract each other

(D) Nothing happens.