Students often asked me what is the difference between force and torque? We might be aware about these terms that is force and torque. Let us understand the concept of force. Force according to a layman is an effort to change the state of a body from rest to motion or from motion to rest and it may also defined as an effort which tries to change the state but it may not change the state. For example, there may be heavy stone and we can try to change its state of rest but we may not be possible to do the same. (more…)
We all are aware about the concept of force, if not then force may be defined as any push or pull that can change the state of rest of an object or can change the velocity of the moving object or can change the direction of the object. Forces can be classified into two types: conservative and non conservative forces. To understand the concept of these two, we also must be aware about the concept of work. The work is said to be done when a body actually moves a distance along the direction of the force. Now let us discuss the difference between the conservative and non conservative force: (more…)
We all know that acceleration is rate of change of velocity. Thus according to this definition, if the velocity of the object is zero or constant, then its acceleration will be zero. But there are certain things in life where only definitions can not define another parameter but these parameters or things may be explained using certain logic. (more…)
In the last article, we have discussed about the 8 advantages of alternating current over direct current. Today we will discuss the disadvantages or drawbacks of ac over dc. Let us discuss them one by one:
- First disadvantage is that the shock of the ac is attractive but the shock of dc is repulsive.
- At high voltages, it is more dangerous to work with ac than dc.
- In the processes like electrorefining, electroplating etc. , one can not use the ac. In these processes, only dc is used.
These are the 3 disadvantages of ac over dc. If you know more, please mention in the comment section.
We all are aware of the concept of ac and dc. There are certain differences between two and also there are advantages and disadvantages or drawbacks of ac over dc. I will discuss the advantages in this article and disadvantages in the next article. Let us discuss them one by one.
Advantages of ac over dc: (more…)
We all must be aware about the meaning of the current. Yes, it is rate of flow of charge. Do you know that when an electric circuit having a ohmic resistance is switched on, the current reaches to maximum value almost in zero time and when the circuit is switched off, the current drops to zero from maximum value in a no time. This you can observe while switching on or off an electric circuit having ohmic resistance only.
But do you know that if there is inductor or capacitor in a circuit, the current will not become maximum from zero or from maximum to zero in no time. The current will take a finite time or one can say it is a gradual process. Thus the electric current which takes finite time to become maximum from zero or zero from maximum in circuits having inductors and capacitors (condensers), then such time of currents are called transient currents.
To understand the concept of interference and conditions for sustained interference, let us first discuss the superposition principle.
Superposition principle enables us to find the resultant of two or more wave motions.
According to this principle, when two or more waves travelling through a medium superimpose upon one another, a new wave is formed in which resultant displacement . at any instant is equal to the vector sum of the displacements due to individual
waves . at that instant
For example, when crest (or trough) of one wave falls on crest (or trough) of the other, the amplitude of the resultant wave is sum of the amplitudes of two waves.
When crest of one wave falls on trough of the other, the amplitude of resultant wave is difference of the amplitude of the two waves. (more…)
In this article, we will discuss about the photon and its properties:
A photon is basically a basic particle which carries with itself electromagnetic energy. The light coming from sun has different wavelengths or energy and on the basis of it, we have different regions like visible, infrared, ultraviolet and many more. But one thing is common in all these regions is photon but of different frequency so different energy.
Thus photon is basically a quantum of light.
Definition of cathode rays:
Cathode rays are the group of fast moving negatively charged particles. These negatively charged particles are electrons. These rays are shot out at a high speed from the cathode of a discharge tube at a pressure below 0.01 mm of mercury.
15 Properties of Cathode rays:
1. Cathode rays travel in straight lines.
2. These rays are deflected by electric field. This is obvious because these rays are nothing but electrons.
3. These rays travel normally from the surface of cathode. (more…)
There are many many field in the area of science to do research. One should be completely dedicated towards his or her work for the same, then sky is the limit only.
Let us discuss few of the science fields to do research and make career. The following fields are the broad area, the sub area under each of these fields are so many and will be discussed later on:
1. Environmental Science: We all know that our environment is getting degraded day by day. Thus there are so many research topics and career avenues in this field. The environment science as a subject is taught from schools. (more…)