Units and Measurement forms the foundation of Physics. This chapter covers fundamental concepts about physical quantities, their measurement, units, dimensions, and error analysis. Understanding these concepts is essential as they apply throughout your Physics syllabus. Physical Quantities Physical quantities are quantities that can be measured and expressed in numerical values with appropriate units. They are …

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Kirchhoff’s laws are two fundamental principles in electrical circuit theory that form the foundation for analyzing complex electrical networks. Named after German physicist Gustav Kirchhoff, who formulated them in 1845, these laws are essential tools for electrical engineers and physicists working with circuits. The laws are based on the principles of conservation of charge and …

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Boolean algebra forms the mathematical foundation of digital electronics and computer systems. Understanding Boolean algebra and logic gates is crucial for analyzing and designing digital circuits, which are at the heart of modern computing devices. 1. Introduction to Boolean Algebra Definition: Boolean algebra is a branch of algebra that deals with binary variables and logical …

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Q1. “Khilafat” movement subsided because of the (a) Concessions given to Muslims by the British (b) Amity achieved between Congress and Muslim League (c) Accession of Kamal Pasha on the throne of Turkey (d) None of the above (UPSC Prelims 1979) Answer: (c) Accession of Kamal Pasha on the throne of Turkey Explanation: The Khilafat …

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Q1. The chemical name for urea is (a) Aneurin (b) Chloroethene (c) Carbamide (d) None of these (UPSC Prelims 1987) Answer: (c) Carbamide Explanation: Urea, a nitrogen-rich compound used in fertilizers, is chemically known as carbamide. It is synthesized from ammonia and carbon dioxide, and plays a key role in agriculture and medicine. Q2. Azolla …

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Mathematics 1. Evaluate the expression: $\csc 10^\circ – \sqrt{3} \sec 10^\circ$ a) 8 b) 6 c) 4 d) 2 (JEE Main 2026 | Exam Date: 21.01.2026 | Shift I) Answer: (c) 4 Solution: Convert the terms into sine and cosine: $$\frac{1}{\sin 10^\circ} – \frac{\sqrt{3}}{\cos 10^\circ} = \frac{\cos 10^\circ – \sqrt{3} \sin 10^\circ}{\sin 10^\circ \cos 10^\circ}$$ …

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1. The sum of all roots of the equation $(x – 1)^2 – 5|x – 1| + 6 = 0$ is: a) 4 b) 1 c) 5 d) 3 (JEE Main 2026 | Exam Date: 21.01.2026 | Shift I) Answer: (a) 4 Solution: Let $|x – 1| = t$. The equation becomes $t^2 – 5t …

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