Tissues — Science STD 9 — Question

The SI unit of thrust is:

Potential energy is directly proportional to:

AIDS is due to:

1. Reduction to number of helper T-cells.
2. Reduction in number of killer T-cells.
3. Autoimmunity.
4. Non-production.

A rectangular wooden block has length, breadth and height of 50 cm, 25cm and 10cm, respectively. This wooden block is kept on ground in three different ways, turn by turn. Which of the following is the correct statement about the pressure exerted by this block on the ground?

1. The maximum pressure is exerted when the length and breadth form the base.
2. The maximum pressure is exerted when length and height form the base.
3. The maximum pressure is exerted when breadth and height form the base.
4. The minimum pressure is exerted when length and height form the base.

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

Dalton’s atomic theory successfully explained:
(i) Law of conservation of mass.
(ii) Law of constant composition.
(iii) Law of radioactivity.
(iv) Law of multiple proportion.

Which of the following vehicles is undergoing a deacceleration?

SPM includes:

1. Flyash.
2. Dust.
3. Soot and smoke.
4. All the above.

Colourless plastids are known as:

One of the following can hear infrasound. This one is: