What is the force acting on a unit area of a surface called?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2: Pressure.
Explanation:
According to Physics, the force acting perpendicularly per unit area of a surface is called Pressure.
• Formula for Pressure:
P = F/A
Where, P = Pressure, F = Force, and A = Area.
• SI Unit: The SI unit of pressure is the Pascal (Pa), which is equivalent to Newtons per square meter (N/m²).
• Relationship: Pressure is inversely proportional to the area. This means that the smaller the area, the greater the pressure exerted (this is why the tip of a nail is kept sharp).
Brief Analysis of Other Options:
• Weight – Option 3: This is the gravitational force with which the Earth pulls an object towards its center. (W = mg)
• Work – Option 4: When a force is applied to an object and the object undergoes displacement in the direction of the force, it is called Work. (W = F × d)
• Force Density – Option 1: This is the force acting per unit volume, typically used in the context of fluids or electromagnetic fields.
Important Facts for Upcoming Exams:
1. Atmospheric Pressure: A barometer is used to measure it.
2. Pascal's Law: This law states that pressure applied to an enclosed fluid is transmitted undiminished in all directions (this principle is utilized in hydraulic lifts).
3. Fluid Pressure: Pressure increases with increasing depth inside a fluid.
Potential Exam Question:
Question: Why can a camel walk easily in the desert?
Answer: Because a camel has wide feet; this increases the surface area, thereby reducing the pressure exerted on the ground. Question: Is pressure a vector or a scalar quantity?
Answer: Scalar quantity.
Question: How many Pascals are equal to 1 Bar?
Answer: 10⁵ Pa.