Physics Short Questions and Answers for Exam Preparation
SECTION B: SHORT QUESTIONS
Q1. Define the Following with Examples
- Frequency (f): The number of complete waves passing a point per second. Unit: Hertz (Hz). Formula: f = 1/T. Example: 50 cycles per second = 50 Hz.
- Wavelength (λ): The distance between two consecutive crests or troughs. Unit: Metre (m). Formula: v = fλ. Example: Visible light is 400–700 nm.
- Time Period (T): The time taken to complete one full vibration. Unit: Second (s). Formula: T = 1/f. Example: A pendulum swing taking 2 seconds.
Essential Physics Concepts: Circuits, Waves, and Mechanics
1. Ohm’s Law, Series, and Parallel Circuits
Q: State Ohm’s Law and derive formulas for series and parallel combinations of resistors.
Answer:
Ohm’s Law:
Ohm’s Law states that the current through a conductor is directly proportional to the potential difference across its ends, provided the temperature remains constant.
Formula: V = IR
Series Combination
In a series circuit, resistors are connected end-to-end.
- The same current flows through all resistors.
- Total voltage is the sum of individual voltages:
Dielectric Polarization, Semiconductors, and Superconductivity
Explain the concept of polarisation in dielectrics. Illustrate and discuss the different types with
diagrams and formulas.The Concept of Polarisation
In a dielectric material, polarization is defined as the process of creating or inducing electric dipoles using an external electric field.
When an external electric field is applied, it interacts with the dielectric in two primary ways:
1 Distortion
The field distorts the internal charge distribution, producing an induced dipole moment in each molecule.
Essential Science Concepts and Global Trade Principles
Core Scientific Definitions
- Scientific Study: A systematic process of acquiring knowledge about the natural world through observation, experimentation, and logical analysis.
- Kingdom Monera: Unicellular prokaryotic organisms such as bacteria and cyanobacteria.
- Organs of Righteousness: In a moral context, the five sense organs and five organs of action used for good deeds.
- Newton’s First Law: An object remains at rest or in uniform motion unless acted upon by an external force.
- Simple Device: A mechanical
Understanding the Compton Effect and Radiation Shifts
Compton Effect, Compton Shift, and Radiation Types
The Compton Effect is a phenomenon in which X-rays or gamma rays scatter off electrons, resulting in a change in wavelength. When a high-energy photon collides with an electron, it transfers part of its energy to the electron. The electron recoils, and the photon emerges with reduced energy and increased wavelength.
The Compton Shift
The Compton Shift is the difference between the initial and final wavelength of the photon after scattering. It is defined
Read MoreCore Principles of Modern Physics: Relativity and Quantum Theory
Frames of Reference
- Inertial frame of reference: A frame at rest or moving with constant velocity where Newton’s First Law of Motion holds true and no extra forces are required.
- Non-inertial frame of reference: A frame that is accelerating or rotating where Newton’s laws require fictitious (pseudo) forces to explain motion.
Laws of Radiation
- Wien’s displacement law: The wavelength at which a body emits maximum radiation is inversely proportional to its temperature (λmax ∝ 1/T and λmaxT = Constant)