Answer: Option B. -> pascal
:
B
The SI unit of pressure is pascal (Pa).
$1Pa=1N/m^2$

Answer: Option A. -> True
:
A
If a force is appliedto a body, the shape of the body can change. For example, the length of an elastic band changes if it is pulled from both ends.

Answer: Option B. -> Pull
:
B
As we can see, the character is pulling the string downwards, so that he canhang. The stringhas to be strong enough to support his weight.

Answer: Option A. -> The block will remain stationary.
:
A
As equal forces are acting on the block in opposite directions, the resultant force is zero. If there is no net force on the block, the state of motion of the block will not change and it will remain stationary.

Answer: Option D. -> 25 Pa
:
D
Given:
Force,$F=50N$
Area, $A=2m^2$
From definition of pressure $\left(P\right)$,
$P=\frac{F}{A}$
$P=\frac{50}{2}=25Pa$

Answer: Option D. -> pressure difference
:
D
When we press the bulb of adropper, the number of air molecules decreases which results in a decrease in pressure inside thedropper nozzle. However, the outside pressure or atmospheric pressureremains the same. Therefore there is a difference in pressure between outside of the nozzle and inside of the nozzle. Since water flows from a region of higher pressure to a region of lower pressure, water rushes to fill inside the dropper.

Answer: Option B. -> False
:
B
Here, the position of the car remainsfixed with respect to time. This means that the car is at rest and there is no change in its state of motion. Hence, the net force on the car is zero and the given statement is false.

Answer: Option A. -> True
:
A
Charges are of two types: positive and negative. From the property of charges, we know that, like charges repel while unlikecharges attract each other.

Answer: Option A. -> True
:
A
Pressure is inversely proportional to the area of contact. For the same force, more surface area results in lesserpressure.
When a porterusesa round piece of cloth on hishead while carrying luggage,the area of contact increases. As a result, pressure decreases.

Answer: Option D. -> frictional force
:
D
Friction is a force that opposes relative motion between two surfaces in contact. A body sliding on a horizontal surface stops because the surface on which it slides resists its motion.