 # Scientific reasons

Why there are two channels in Oscilloscope? Do we need to connect both channels to observe a waveform on it?

REASON:

A two-channel oscilloscope allows you to contrast an info signal with a yield signal, and on the off chance that you had a way to control the conduct DUT (gadget under test) in the middle of the two tests at that point having the option to see the information and yield all the while can help you settle on better choices on its exhibition. No , we do not need to connect both channels.

Why there are color bands on a resistor?

Color-coding is a method used to indicate the resistive value, tolerance, and temperature coefficient of resistors with low wattage rating because of their small size. Color bands are used because they can be easily and cheaply printed on a small electronic component. Color-coding is also used for capacitors, inductors and diodes.

Why we use SI units for measurements? If we have measurement in any other unit what we do?

SI units provide a way for scientists around the world to record information about observations in a manner that all scientists around the world will understand. Imagine if scientists in the US had one way of measuring mass, scientists in Europe had a different method, and scientists in Asia had a third method

If we have a resistor physically but its color bands are not visible, then how can we calculate the value of resistor?

If we have a resistor physically but it’s color bands are not visible, then value of current can be calculated by using ohm’s law.

If we change the frequency of a wave to twice what will be the effect on time of wave?

Doppler effect, the apparent difference between the frequency at which sound or light waves leave a source and that at which they reach an observer, caused by relative motion of the observer and the wave source. This phenomenon is used in astronomical measurements,

If we change the amplitude of wave is there any effect appear on time?

If you change the amplitude of a sound wave, you change its power and intensity. You also change its perceived loudness. In more general terms, you are changing the energy content of a sound wave when you change its amplitude. The amplitude of a sound is a measure of the change in pressure (force over a given area) that it exerts on the air through which it passes.

The power of a sound is its amplitude over a given period of time. Power, like electrical power, is expressed in Watts, which is equal to 1 Newton of force per second. An increase in amplitude therefore causes a corresponding increase in power.

In a parallel circuit there are 4 resistors connected (4kΩ,2kΩ,1kΩ,7kΩ) Which resistor will have the maximum voltage drop and Why?

Individual resistors can be connected together in either a series connection, a parallel … REQ = R1 + R2 + R3 = 1kΩ + 2kΩ + 6kΩ = 9kΩ … voltage drop and power for each resistor in the following resistors in series circuit.

If there is one resistor in a circuit and we change the value of resistor, what will be the effect on voltage and current of the circuit?

Sometimes you need a resistor with a value you don’t have in your kit. Instead of ordering and wanting for a resistor with a value you need you can change the resistance of a resistor by using another resistor or many. By installing resistors in a parallel or series circuit you can change the value in Ohms.

Which circuit Series or Parallel have the maximum power rate in resistors? Why?

Series. Series have a high power rate.

1. What is the role of 4th resistor in a 4 band resistor?

**A four band resistor will have two bands giving two digits of the value, third band is a multiplier (number of zeros to follow the first two digits), and the fourth band indicates the tolerance - silver is +/-10%, gold is +/- 5% A five band resistor will have three bands giving the first three digits of the value, and will be +/- 2% or better.is the role of 4th resistor in a 4 band resistor