Answer:
b. There is no definite top to the atmosphere. The pressure and density gradually get smaller as the altitude gets larger.
Explanation:
There is no specific top of the atmosphere. It varies from place to place. But generally it is considered to be 480 kilometers thick. But majority of its thickness is limited to 16 km only above earth surface. The pressure and density gradually get smaller as the altitude gets larger. The air pressure at sea level is 14.7 pounds per square inch and it decreases to 10 pounds per square inch at a height of 3 kilometers. From the above discussion we say that option B is correct
Answer:
The value of the power is
Explanation:
From the question we are told that
The power rating
The frequency is
The frequency at which the sound intensity decreases
The decrease in intensity is by
Generally the initial intensity of the speaker is mathematically represented as
Generally the intensity of the speaker after it has been decreased is
So
=>
=>
=>
=>
=>
taking atilog of both sides
=>
=>
=>
Answer:
D. There is a magnetic force pushing the wires away from one another.
Explanation:
When electric current flows through one wire then it will induce magnetic field now this magnetic field will exert the force on another current carrying wire
Now we know that force between two current carrying wires is given as
so here if two wire have current in same direction then two wires will attract each other
Also when current in wire is anti parallel to each other then the force between two wires is repulsive force
so correct answer will be
D. There is a magnetic force pushing the wires away from one another.