“In Pascal’s law we find that pressure does not increase with area. But when we study about pressure, we learn that pressure is inversely proportional to area. How is this possible? Please explain.”
Fahad Imtiaz asked via Speak Pipe
Pressure is defined as the thrust (the total force acting normal to a surface) per unit area.
Pascal’s law deals with fluid pressure and the statement goes –
“The pressure exerted anywhere in an enclosed incompressible and non-viscous fluid is transmitted equally and undiminished in all directions through out the fluid, provided the effect of gravity is neglected”
Read the statement carefully.
Here we are not changing the definition or meaning of pressure.
the fact to note that, in an enclosed fluid, the pressure is transmitted equally throughout the fluid. Therefore, if we apply some pressure somewhere in the fluid, the same pressure will be felt at any other place on the enclosed fluid. This gives us an opportunity to multiply the force. Since the pressure is equal everywhere, if we increase the area the force (thrust) is increased.
P = F/A or F = PA
So, pressure remaining constant, greater the area, greater is the force.
Hope you understand the matter now.
Please explain what is transformer and tell what is the reason behind the working of transformer that it reduces potenial when current is high and increases potential when current is low?
Explain widely and deeply with concepts.
Transformer is a device based on mutual inductance and is used to change the voltage of alternating (or varying) current. There are two types of transformers – stepup and stepdown.
A step-up transformer increases the voltage as the step-down transformer decreases the ac voltage.
When a transformer changes the alternating voltage, it is not adding any power, it only transforms the voltage.
As power is the product of voltage and current, as voltage increases, the current decreases. (and vice versa)
The following links will help you understand transformers in great detail.
Categories: Ask Physics, Current Electricity, Electromagnetism, Electronics, physics, Physics Videos Tags: Business, Electrical, Electronics and Electrical, High voltage, Inductance, Power Supplies, Substation and Transmission, transformer, Transformers and Inductors, Voltage
What about the correctness about the relation,
st=u+0.5a(2t-1), both dimensionally or any other
Prakash Adhikari asked
The equation refers to the displacement in the tth second and hence it should have the dimensions of speed; since it is the displacement in one second.
Under this consideration, the equation is dimensionally and otherwise correct.
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