EducatorSharmin

  Modern Physics & Electronics Albert Einstein was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics). He is best known for his mass-energy equivalence formula  E = mc2. He received the 1921 Nobel Prize in Physics for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect, a pivotal step in the evolution of quantum theory.                                            Modern Physics & Electronics Q. What is radioactivity? Radioactivity is the emission or transmission of ions in the form of waves or particles through space or a material medium by the spontaneous disintegration of atomic nuclei. It is a Nucleic Phenomenon. Three types of rays emitted from radioactive atoms- Alpha - particle is a helium nucleus Beta ...

   Physics  Magnetic Effects of Current Chapter-12 Question/Answer: 1. What is the magnetic effect of current flow? Ans: If current flows through a conductor, a magnetic field is created around it. This is known as the magnetic effect of current flow. 2. What is the fundamental principle of electrical motor? Ans: Effects of the magnet on the current flowing wire. 3. What is an electric motor? Ans: An electrical motor is a machine, that converts electrical energy into mechanical energy. 4. How to increase the intensity of an electromagnet? Ans: By increasing current flow, increasing the number of turns in the solenoid, by bending the solenoid like 'U' letter, the intensity of an electromagnet can be increased. 5. What is induced current flow? Ans: By changing the distance of a movable magnet or current flowing circuit or by changing the current flow, the temporary flow that is created on the closed circuit, is known as induced current flow. 6. What is electromagnetic induc...

  Current Electricity: The amount of charge that flows in unit time through any cross-section of a conductor is called an  electric current . Electric current is the flow of electric charge across a surface, point, or region. The amount of energy required by an electric source to transfer unit positive charge from one point of the circuit and bring it there again by traveling the total circuit is called the  electromotive force  of that source. The work done by an energy source to drive a unit positive charge around a circuit from one point back to the same point is called the  electromotive force  of that source. The work done to bring a unit positive charge from an infinitive distance to any point of the electric field is called the  electrical potential  of that point. The materials through which electric current can flow very easily are called conductors . Electrons can flow freely within these materials. In metal wires, the charges are carrie...

  Ratio & Proportion: A ratio is used to compare two or more quantities of the same kind which are measured in the same unit. It is a comparison of two different things or numbers. We generally express the two numbers as a ratio using a colon (:). The colon is read as “is to”.   Proportion: It is a pair of equal ratios. The product of the means is equal to the product of extremes.  Direct Proportion: Two quantities are said to be directly proportional if change in one produces a change in the other in same direction. Indirect Proportion: Two quantities are said to be indirectly proportional if an increase in one produces a decrease in the other, or vice versa. Partitive Proportion: A number is divided into equal parts proportional to a given ratio. It involves part to whole ratios equivalent to each other. Example: Two jeepneys can transport 40 people. How many jeepneys are needed to transport 80 people? Four men can complete a project in 9 days. How many men ...