The Fundamental Unit of Life — Science STD 9 — Question

Cells were determined to be the basic structural units of plants and animals, in which of the following time period?

Forest destruction results in:

1. Loss of wild life.
2. Floods and drought.
3. Soil erosion.
4. All of these.

Almost all of the mass of an atom is concentrated at the

A car is accelerated on a levelled road and acquires a velocity 4 times of its initial velocity. During this process, the potential energy of the car:

1. Does not change.
2. Becomes twice that of initial potential energy.
3. Becomes 4 times that of initial potential energy.
4. Becomes 16 times that of initial potential energy.

The universal law of gravitation gives the gravitational force between

Which of the following is incorrect for green manure?

Which of the following is not a longitudinal wave?

A motorcycle and a car start from rest at the same place at the same time and travel in the same direction.The motorcycle accelerates uniformly at 1m/ s² up to a speed of 36km/ h and the car at  0.5m/ s² up to a speed of 54km/ h.Then the distance at which the car overtakes the cycle-

One of the following is a solid foam. This one is:

1. Butter.
2. Bread.
3. Shaving cream.
4. Ruby.

Area under a v – t graph represents a physical quantity which has the unit: