What is friction in physics - Friction, Physics, class 11 - eSaral
Friction is the opposing force that is set up between the surfaces of contact. If you want to learn what is friction in physics then keep reading. Friction Friction is the opposing force that is set up between the surfaces of contact when one body slides or rolls or tends to do so on the surface of another body. For example, if a book on a table slides from left to right along the surface of a table, a frictional force directed from the right to left acts on the book at the surface of contact i....
Read More →What is dynamic friction in physics - Friction, Class 11 - eSaral
Hey, do you want to know What is dynamic friction in physics? If yes. Then keep reading. Dynamic Friction When the force acting on the body is greater than the limiting friction, then the body comes into motion. The friction now acting between the surfaces of contact is dynamic friction. The dynamic friction is always less than the limiting static friction. Dynamic friction is of two types: Sliding Friction Rolling Friction Sliding Friction: If one body begins to slides over the other, then the ...
Read More →What is Static Friction - Friction, Physics, Class 11 - eSaral
Hey, do you want to know what is Static Friction? If yes. Then keep reading. Static friction The frictional force between two surfaces before the relative motion actually starts is called static frictional force or static friction. If we slowly increase the force with which we are pulling the box, the graph shows that the friction force increases with our force up to a certain critical value, $\mathrm{f}_{\mathrm{L}}$, the box suddenly begins to move, and as soon as it starts moving, a smaller f...
Read More →Motion in a lift - Laws of Motion, Physics, Class 11 - eSaral
eSaral Class 11 Physics Motion in a Lift What is Apparent Weight and Why Does It Change in a Lift? Your actual weight is the gravitational force Earth exerts on you: $W = Mg$ This never changes as long as your mass and $g$ remain constant. Your apparent weight, however, is the force you feel the normal reaction $N$ that the floor of the lift pushes back on you. When the lift is stationary or moving at constant velocity, $N = Mg$, so apparent weight equals actual weight. The moment the lift accel...
Read More →Frame of reference in physics - Inertial and Non-inertial - eSaral
A non-accelerating frame of reference is called an inertial frame of reference. If you want to learn more about the frame of reference in physics. Then keep reading. Inertial and accelerated frames of reference (a) Inertial frames of reference: A non-accelerating frame of reference is called an inertial frame of reference. A frame of reference moving with a constant velocity is an inertial frame of reference. All the fundamental laws of physics have been formulated in respect of the inertial fra...
Read More →Motion of bodies connected by strings - Physics Class 11 - eSaral
Hey, do you want to learn about the motion of bodies connected by strings? If yes. Then you are at the right place. The motion of bodies connected by strings Two bodies : Let us consider the case of two bodies of masses $\mathrm{m}_{1}$ and $\mathrm{m}_{2}$ connected by a thread and placed on a smooth horizontal surface as shown in fig. A force F is applied on the body of mass $\mathrm{m}_{2}$ in forwarding direction as shown. Our aim is to consider the acceleration of the system and the tension...
Read More →Motion of bodies in contact - Physics Class 11 - eSaral
Hey, do you want to learn about the motion of bodies in contact? If yes. Then you are at the right place. The motion of bodies in contact (a) When two bodies of masses $\mathrm{m}_{1}$ and $\mathrm{m}_{2}$ are kept on the frictionless surface and a force F is applied on one body, then the force with which one body presses the other at the point of contact is called Force of Contact. These two bodies will move with same acceleration = a. When the force F acts on the body with mass $\mathrm{m}_{1}...
Read More →Applications of impulse - Impulse, Physics - eSaral
Hey do you want to learn about the applications of impulse? If so, Then you are at the right place Impulse It is not convenient to measure the varying force of impact. Suppose that $\overrightarrow{\mathrm{F}}$ av is the average force acting during impact and $t$ is the small-time for which the impact lasts. In such situations, it is found that the quantity Fav. It is very easy to measure. The quantity $\overrightarrow{\mathrm{F}}_{\text {av }} . \mathrm{t}$ is called impulse. If a variable forc...
Read More →Horizontal Projectile motion - Motion in Plane - eSaral
Hey, do you want to learn about Horizontal projectile motion? If yes. Then you are at the right place. Horizontal Projectile motion Suppose a body is thrown horizontally from point O, with velocity u. Height of O from ground = H. Let X-axis be along horizontal and Y-axis be vertically downwards and origin O is at point of projection as shown in fig. Let the particle be at P at a time t. The co-ordinates of P are (x, y) Distance travelled along X-axis at time t with uniform velocity i.e. Velocity...
Read More →Oblique Projectile motion - Motion in Plane - eSaral
Hey, do you want to learn about the Oblique Projectile motion? If yes. Then keep reading. Oblique Projectile motion Consider the motion of a bullet which is fired from a gun so that its initial velocity $\overrightarrow{\mathrm{u}}$ makes an angle $\theta$ with the horizontal direction. Let us take $X$ -axis along ground and Y-axis along vertical. $\overrightarrow{\mathrm{u}}$ can be resolved as $\mathrm{u}_{\mathrm{x}}=\mathrm{u} \cos \theta \quad$ (along horizontal) $\ u_{y}=u \sin \theta$ (al...
Read More →Motion in two dimensions - Motion in Plane - eSaral
An object moving in a plane is said to have two-dimensional motion. If you want to learn more about Motion in two dimensions. Then read this article till the end. Motion in Two Dimensions An object moving in a plane is said to have two-dimensional motion. The two-dimensional motion is equal to the vector sum of two one-dimensional motions along a mutually perpendicular direction. Let the position of point P at a time t be given by position vector $\overrightarrow{\mathrm{OP}}=\overrightarrow{\ma...
Read More →State the law of radioactive decay - Radioactivity, Physics - eSaral
Hey, students do you want to know how to state the law of radioactive decay? If yes. Then read this article till the end. Radioactive decay law The rate of decay (number of disintegrations per second) is proportional to number of radioactive atoms (N) present at that time t rate of decay $\frac{-\mathrm{d} \mathrm{N}}{\mathrm{dt}} \propto \mathrm{N}$ or $\frac{\mathrm{d} \mathrm{N}}{\mathrm{dt}}=-\lambda \mathrm{N}$ or $\quad N=N_{0} e^{-\lambda t}$.....(1) where $\lambda$ is disintegration cons...
Read More →Uses of radioactive isotopes - Radioactivity, Physics - eSaral
Hey, do you want to learn about the uses of radioactive isotopes? If yes. Then you are at the right place. Uses of radioactive isotopes In Medicine a. $\mathrm{Co}^{60}$ for treatment of cancerb. $\mathrm{Na}^{24}$ for circulation of blood c. $\mathbf{I}^{131}$ for thyroid d. $S r^{90}$ for treatment of skin eye e. $\mathrm{Fe}^{59}$ for location of brain tumor f. Radiographs of castings and teeth In Industries a. For detecting leakage in water and oil pipe lines b. For investigation of wear tea...
Read More →Working of NPN and PNP transistor - Electronics, Physics - eSaral
eSaral Class 11 Working of NPN and PNP transistor 🚀 Checkout eSaral Courses Hey, do you want to learn about the Working of NPN and PNP transistor? if yes. Then you are at the right place. P-N-P Transistor: The holes of the P region (emitter) are rippled by the positive terminal of battery $\mathrm{V}_{\mathrm{EE}}$ towards the base. The potential barrier at the emitter junction is reduced as it is forward bias and hence the holes cross this junction and penetrate into the N region. This constitu...
Read More →What is Transistor and its types - Physics, Electronics - eSaral
A Transistor is an electronic device formed by P and N types of semiconductors. If you want to know about what is transistor and its types then read this article till the end. Transistor Transistor is used in place of triode valve, it is an electronic device formed by P and N types of semiconductors. It was discovered by American scientist J Barden, W.H. Bratain, W. Shockley. The transistor is three-terminal and two P-N Jn. device. There are two types of transistors N-P-N transistor P-N-P transi...
Read More →Different types of PN-junction diodes - Electronics - eSaral
Diode is a PN junction device. If you want to know about the different types of PN-junction diodes then keep reading. Different types of PN-junction diodes 1. Light Emitting Diode (LED) Very much used in a dancing light display of music systems and information boards on railway stations. In a forward-biased diode, the energy produced by recombination of electrons and holes at the junction can be emitted. If the energy is in the visible region, such a diode is called a light-emitting diode or LED...
Read More →Bridge rectifier circuit diagram - Definition, Efficiency - eSaral
Bridge Rectifier is also a full-wave rectifier. If you want to learn about the Bridge rectifier and Bridge rectifier circuit diagram then keep reading. Bridge Rectifier It is also a full-wave rectifier. Use of bridge rectifier The bridge rectifier is used in the rectifier type voltmeter. The circuit arrangement is shown in fig. The rectifier elements are p-n junction diodes with a sensitive DC. ammeter as a load. This circuit can be used for the measurement of AC as well as DC voltage and curren...
Read More →Full wave rectifier circuit diagram - Definition, Ripple Factor - eSaral
A device that rectifies both halves of the ac input is called a full-wave rectifier. If you want to learn about the full-wave rectifier and full-wave rectifier circuit diagram then keep reading. Full-wave rectifier: A rectifier that rectifies both halves of the ac input is called a full-wave rectifier. During the first half of the input cycle, the upper end of S coil is at positive potential and the lower end is at the negative potential the junction diode $\mathrm{D}_{1}$ will get forward biase...
Read More →Half wave rectifier circuit diagram - Definition, Explanation - eSaral
A device that converts alternating current into Direct current is called a rectifier. If you want to learn about the half-wave rectifier and half-wave rectifier circuit diagram then you are at the right place. Application of diode as a rectifier: An electronic device that converts alternating current into Direct current is called a rectifier. Half wave rectifier: A rectifier, which rectifies only one half of each ac supply cycle is called a half-wave rectifier. During the first half of the input...
Read More →What is Diode in electronics - Definition, Important Points - eSaral
A diode is a PN junction device. If you want to know what is diode in electronics. Then keep reading. Diode A diode is a PN junction device Ideal diode Conducts with zero resistance when forward biased. Offer an infinite resistance when reverse biased. Practical Circuit For diode The practical characteristic curve for a diode: Important terms related to diode: Knee VoltageKnee voltage is defined as the forward voltage at which the current through the junction starts increasing rapidly.For silico...
Read More →What is P-N junction - Definition, Explanation, Types - eSaral
P-N junctions are formed by diffusing trivalent impurity to one-half side and pentavalent impurity to another side. If you want to know what is P-N junction then keep reading this article. P-N Junction By merely Joining the two pieces a P-N Junction cannot be formed. P-N junctions are formed by diffusing trivalent impurity to one-half side and pentavalent impurity to another side. The plane dividing the two zones is known as a junction. P-N junction is unohmic As P-type semiconductor has a high ...
Read More →What is Fermi energy level in semiconductors - Electronics - eSaral
Hey, Do you want to know what is fermi energy level in semiconductors? If yes. Then keep reading. Fermi Energy Level. Fermi energy is the maximum kinetic energy of an electron at 0 K these electrons are called Fermi electrons and energy level is known as Fermi energy level. It is always found between the conduction band and valance band Fermi Level is the energy that corresponds to the center of gravity of the conduction electrons and holes weighted according to their energies. In pure germanium...
Read More →Types of Semiconductors - Types, Examples - eSaral
Semiconductor in an extremely pure form is known as an intrinsic semiconductor and The impure semiconductor material is called an extrinsic semiconductor. If you want to learn about the Types of Semiconductors then keep reading. Types of Semiconductors Pure or intrinsic semiconductor: A semiconductor in an extremely pure form is known as an intrinsic semiconductor. In an intrinsic semiconductor, the number of free electrons is always equal to the number of holes when an external field is applied...
Read More →Effect of Temperature on semiconductor - Electronics - eSaral
Hey, do you want to learn about the Effect of Temperature on Semiconductor? If yes. Then keep reading. Effect of Temperature on Semiconductor At Absolute zero temperature Covalent Bonds are very strong and there is no free electron in the conduction band. For semiconductors at 0 K, the conduction band is empty while the valence band is full. Above Absolute zero temperature When temperature increases some of the covalent bonds are break due to thermal energy supplied. At room temperature, due to ...
Read More →Classification of solids in terms of the forbidden energy gap - eSaral
hey, do you want to learn about the Classification of solids in terms of the forbidden energy gap? If yes. Then you are at the right place. Classification of solids in terms of the forbidden energy gap The width of the forbidden energy gap between the valence band and the conduction band distinguishes conductors, semiconductors, and insulators from each other. Comparison between conductor, semiconductor, and insulator: Difference between Valence, Conduction, and Forbidden Band Valence band: This...
Read More →