Answer:
When you use your control remote, you can see that there is not a "material" thing that comes out of the control remote and goes to the TV, but there is actually energy that comes from the control remote (and this is why your control remote needs battery)
This energy is called an "electromagnetic wave" usually in the infrared range, this means that the energy that comes from the control remote has less energy than the visible red light (and this is why we can not see the light that comes out of the control remote), and this "signal" is read by the TV, in order to change of channel or change the volume.
You even can see that there is a sort of light (electromagnetic wave) coming out from it if you point with a camera to the small bulb that is in the front of the control remote.
Answer:
3.body
Explanation:
Both P and S waves are both body waves. Body waves are waves that travels through the earth.
P and S waves are elastic seismic waves that moves within the earth. Love and Rayleigh waves are surface waves that travels through the surface.
- P waves is also known as primary waves
- S waves are known secondary waves.
These waves are the first set of waves to arrive a seismic station before the surface waves are picked up.
Answer:
Explanation:
Case-A
Block weight 
Friction Force 
and friction force is

where N=normal reaction (Usually equals to weight)


Case-B
Block weight 
Friction Force 



Case-C
Block weight 
Friction Force 



The mass of the petcock of the pressure cooker is 0.257 kg.
The total pressure inside the cooker is= atmospheric pressure+Gauge pressure
=100 kPa+101 kPa=201*10^3 Pa
The area of the petcock is= (π/4)d^2=0.785*0.004^2=12.56*10^(-6) m^2
Now the mass of the petcock is calculated as
P=(F/A)=(mg/A)
201*10^3=(m*9.81/(12.56*10^(-6)
m=0.257 kg
Therefore the mass of the petcock is 0.257 kg
False ! energy can not be created and for generators , they convert mechanical energy to electrical energy !