basic electronics
What's the difference between resistance and resistivity?
Resistance is the obstruction offered to the flow of current by a conductor.
Resistivity is the obstruction offered to the flow of current by UNIT AREA OF the conductor.
So basically, resistance is the property of the object (say a copper wire), whereas resistivity is the property of the substance (copper).
And so resistance depends upon the properties of the object.
Whereas resistivity depends upon the properties of the metal.
So for example take two objects A and B made of aluminium. Both are of a different size.
The resistance of A & B will be different.
But the resistivity will be the same.
Why do we need modulation and carrier wave?
In simple terms, modulation is required to transmit signals from variuos sources simultaneously over a common channel by means of 'multiplexing'.For ex., the bandwidth of speech signals is 3.3KHz.,and transmitting N no.of speech signals simultaneously each of BW 3.3KHz causes interference.Hence,to overcome this problem, each speech signal is modulated onto one of N carriers of frequencies 60KHz,64KHz,68KHz etc... I know that why we use Carrier of high frequency to send message signal over a long distance, when the frequency is low , energy will be obviously low. To increase the energy of the signal we need to increase the frequency. This is achieved by multiplying the message signal with the carrier signal (with high frequency). suppose, Carrier signal frequency = 2800KHz message signal frequency = 3KHz the two generated sidebands will be ,
2800 + 3 = 2803 KHz 2800 - 3 = 2797 KHz and eventually, the bandwidth of the signal is,
BW = 2803 - 2797 = 6KHz this is when the carrier frequency is higher , and we noticed that bandwidth is just twice of the highest frequency of modulating signal. and the signal will be easily demodulated at the receiver end.
WHAT IS RPS?
INTRODUCTION
There are several ways to convert an AC voltage at a wall receptacle into
Resistance is the obstruction offered to the flow of current by a conductor.
Resistivity is the obstruction offered to the flow of current by UNIT AREA OF the conductor.
So basically, resistance is the property of the object (say a copper wire), whereas resistivity is the property of the substance (copper).
And so resistance depends upon the properties of the object.
Whereas resistivity depends upon the properties of the metal.
So for example take two objects A and B made of aluminium. Both are of a different size.
The resistance of A & B will be different.
But the resistivity will be the same.
Why do we need modulation and carrier wave?
In simple terms, modulation is required to transmit signals from variuos sources simultaneously over a common channel by means of 'multiplexing'.For ex., the bandwidth of speech signals is 3.3KHz.,and transmitting N no.of speech signals simultaneously each of BW 3.3KHz causes interference.Hence,to overcome this problem, each speech signal is modulated onto one of N carriers of frequencies 60KHz,64KHz,68KHz etc... I know that why we use Carrier of high frequency to send message signal over a long distance, when the frequency is low , energy will be obviously low. To increase the energy of the signal we need to increase the frequency. This is achieved by multiplying the message signal with the carrier signal (with high frequency). suppose, Carrier signal frequency = 2800KHz message signal frequency = 3KHz the two generated sidebands will be ,
2800 + 3 = 2803 KHz 2800 - 3 = 2797 KHz and eventually, the bandwidth of the signal is,
BW = 2803 - 2797 = 6KHz this is when the carrier frequency is higher , and we noticed that bandwidth is just twice of the highest frequency of modulating signal. and the signal will be easily demodulated at the receiver end.
WHAT IS RPS?
INTRODUCTION
There are several ways to convert an AC voltage at a wall receptacle into