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Chemistry: Solid state

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  ```html Solid State - (Part 1) Chapter: Solid State Topics Covered: Introduction Types of Solids Isomorphism & Polymorphism Classification of Crystalline Solids Crystal Structure Unit Cell Cubic Crystal System 1.1 Introduction A solid is a state of matter in which particles are held together by strong intermolecular forces. Therefore, solids have: ✔ Definite shape ✔ Definite volume ✔ Very little compressibility ✔ Very small effect of temperature and pressure The constituent particles of solids may be: Atoms Ions Molecules Exam Tip: Strong interparticle forces are responsible for the definite shape and volume of solids. 1.2 Types of Solids Solids are classified into two types: Crystalline Solids Amorphous Solids A. Crystalline Solids Definition: A crystalline solid is a solid in which particles are arranged in a regular, repeating and orderly pattern. Properties Regular arrangement of particles (Long-range ...
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Sex-linked inheritance means the passing of traits (characteristics) through the sex chromosomes (X and Y) from parents to their children. It is called sex-linked because the genes are present on the X chromosome , Y chromosome , or both X and Y chromosomes . There are 3 types : X-linked inheritance – The gene is present only on the X chromosome . Example: Haemophilia. Y-linked inheritance – The gene is present only on the Y chromosome . These traits are passed only from father to son , because only males have a Y chromosome. XY-linked inheritance – The gene is present on both the X and Y chromosomes (usually in matching regions), so it can be inherited by both males and females. In one line: Sex-linked inheritance = Passing of genes located on the X or Y chromosomes from parents to their children.
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Chromosome

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Disorders & Diseases

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 Thalassaemia is an inherited blood disorder. It happens when a child receives faulty haemoglobin genes from one or both parents. Step-by-step: Haemoglobin is the protein inside red blood cells that carries oxygen. Haemoglobin is made of protein chains called alpha chains and beta chains . The instructions for making these chains are stored in genes. If there is a mutation (change) in these genes, the body cannot make enough normal haemoglobin. As a result, red blood cells become weak, small, and are destroyed more quickly than normal. This leads to anaemia (low number of healthy red blood cells). How is it inherited? If both parents are carriers of thalassaemia trait: 25% chance the child will have normal genes. 50% chance the child will be a carrier (thalassaemia minor). 25% chance the child will have thalassaemia major (severe disease).
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Semiconductors Devices PYQs

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  Semiconductor Devices Important Questions & Answers Semiconductor Devices - Important Questions & Answers Q.1 (x) CE Amplifier In common emitter amplifier, current gain is 80 and emitter current is 9 mA. Find base current. Given: β = 80, IE = 9 mA IE = IB + IC β = IC / IB = 80 IC = 80IB 9 = IB + 80IB 9 = 81IB IB = 9/81 = 1/9 mA Answer: (d) 1/9 mA Q.2 (vi) Phase Difference in CE Amplifier In a Common Emitter (CE) amplifier, the output voltage is 180° out of phase with the input voltage. Q.16 Light Emitting Diode (LED) Definition: A Light Emitting Diode (LED) is a p-n junction diode that emits light when forward biased. Working: LED is forward biased. Electrons and holes move towards the junction. Recombination occurs near the junction. Energy is released as light. The LED glows. March 2022 Q.2 (iv) Write the Boolean expression for X-OR gate. Y = A̅B + AB̅ Q.28 What is a Rectifier? A rectifier is an electronic de...
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Electrical Shift During Depolarization of Ovum during fertilization

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The egg's membrane is like a battery. Before a sperm enters, the egg membrane has a voltage difference across it: Membrane Potential = V inside − V outside ≈ −70 mV This means: The inside of the egg is more negative than the outside. There are more positive ions outside the cell and relatively more negative charge inside. This condition is called the resting membrane potential . What Happens When the First Sperm Fuses? The sperm's contact opens ion channels in the egg membrane. Large numbers of sodium ions (Na⁺) rush into the egg because: Sodium concentration is higher outside the cell. Sodium ions carry a positive charge. They naturally move into the cell through the opened channels. Why Does the Voltage Change? Imagine: Inside charge = −70 units Outside charge = 0 units When many positively charged sodium ions enter: The inside becomes less negative. Then it becomes neutral. Then it becomes positive. The membrane potential chang...
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Semiconductor Devices

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BJT Notes | Unified Typography | Semiconductor Devices 🔌 Bipolar Junction Transistor (BJT) — Teaching Notes / Gist 📘 Bipolar Junction Transistor (BJT) 📖 Definition A transistor is a semiconductor device having: Two p-n junctions Three terminals Current in transistor is due to: Electrons Holes 🔁 Therefore it is called: Bipolar Junction Transistor 💡 One-line Definition “A BJT is a semiconductor device used for amplification and switching.” 🔹 Types of Transistors NPN transistor PNP transistor 📢 NPN transistor is more commonly used. 🏗️ Structure of BJT A transistor has three regions: Region Symbol Function Emitter E Supplies charge carriers Base B Controls transistor action Collector C Collects cha...
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Std 10: Heredity and Evolution notes

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1. Complete the following diagram.   Ans)  a) Palaeontological b) Embryological Q.2. Read the following statements and justify the same in your own words with the help of suitable examples. a. Human evolution began approximately 7 crore years ago. Answer: The Earth's ice age began approximately 7 crore years ago. During this period, dinosaurs became extinct. Mammals started evolving and diversifying rapidly. Due to climatic changes, forest cover reduced significantly. The ancestors of monkey-like animals were Lemur-like animals that developed during this time. Around 4 crore years ago, these monkey-like animals gradually lost their tails. Their body size and brain capacity increased, leading to the evolution of ape-like mammals. These monkey-like ancestors shared evolutionary links with apes and human-like creatures. Human evolution was marked by an increase in brain size, the abili...
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