Instasolv

IIT-JEE NEET CBSE NCERT Q&A

4.5/5

# Xam Idea Class 12 Physics Solutions

Xam Idea Class 12 Physics Solutions are curated by subject experts of Instasolv following the latest CBSE syllabus of Physics so that you can learn the concepts more efficiently. Xam Idea solutions for Class 12 Physics contain verified answers provided by highly qualified physics faculty.

Xam Idea Class 12 Physics Book contains all types of questions like very short answer questions, short answer and long answer questions for your thorough practice. Besides, it also contains problems from past year question papers. Xam Idea solutions for Class 12 Physics cover all the topics extensively. The significant topics covered are electric charges and fields, current electricity, electrostatic potential and capacitance, moving charges and magnetism, alternating current, magnetism and matter, electromagnetic induction, electromagnetic waves, optical instruments and ray optics, wave optics, and dual nature of matter. You also get to know about radiation, atoms, nuclei, electronic devices, communication systems.

Xam Idea Class 12 Solutions for Physics are detailed and explanatory in a unique way. You will find step-by-step solutions for numerical value questions, answers for all logical reasoning questions and informative answers to all theoretical questions. We assure you that our solutions provide necessary guidelines to score good marks in the class 12 exam.  These are good for in-depth learning of the concepts during your learning phase and effective revisioning during examinations.

Class 12

## Xam Idea Class 12 Physics  Solutions: Chapter-wise

All the topics covered in Xam Idea Class 12 Physics and their essential components are discussed below. The questions asked in this book are of the following types – very short answer questions (VSAQ), short answer questions (SAQ), and long answer questions (LAQ). The chapter-wise details are given below-

## Xam Idea Class 12 Physics Chapter 1 (Electric Charges and Fields) Solutions

In this chapter, you learn about electric charge, conductors and insulators, charging by induction, basic properties of electric charge and additivity of charges. You also learn that charge is conserved, quantisation of charge, Coulomb’s law, forces between multiple charges, electric field, electric field due to a system of charges and the physical significance of the electric field.

Further, you learn regarding electric field lines, electric flux, electric dipole and its field, the physical significance of dipoles, dipole in a uniform external field, continuous charge distribution, Gauss’s law and its applications, field due to an infinitely long straight uniformly charged wire; infinite plane sheet; and thin spherical shell. This chapter has 26 VSAQs, 25 SAQs and 10 LAQs.

## Xam Idea Class 12 Physics Chapter 2 (Electrostatic Potential and Capacitance) Solutions

Chapter 2 of Xam Idea Class 12 Physics book teaches you about electrostatic potential, potential due to a point charge; an electric dipole; a system of charges and equipotential surfaces. Further, you learn about the relation between field and potential, potential energy of a system of charges; in an external field; of a single charge; of a system of two charges in an external field and potential energy of a dipole in an external field.

You also learn about electrostatics of conductors, dielectrics and polarisation, capacitance and capacitors, the effect of dielectric on capacitance, the parallel plate capacitor, combination of capacitors, capacitors in series, capacitors in parallel, energy stored in a capacitor and van de Graaff generator. You will find 41 VSAQs, 48 SAQs and 10 LAQs in this chapter.

## Xam Idea Class 12 Physics Chapter 3 (Current Electricity) Solutions

Current Electricity chapter teaches you all about electric current, electric currents in conductors, Ohm’s law, the drift of electrons and the origin of resistivity, mobility and limitations of Ohm’s law. Further, you come to know about resistivity of various materials, the temperature dependence of resistivity, electrical energy, power, a combination of resistors – series and parallel.

Next, you learn about cells, emf, internal resistance, cells in series and parallel, Kirchhoff’s rules. You also learn about the types of equipment such as Wheatstone bridge, meter bridge and potentiometer. This chapter contains 57 VSAQs,  85 SAQs and 13 LAQs.

## Xam Idea Class 12 Physics Chapter 4 (Moving Charges and Magnetism) Solutions

The 4th chapter of Xam Idea Class 12 Physics Solutions teaches you everything about magnetic force, its sources and fields. You learn about the magnetic field, Lorentz force, the magnetic force on a current-carrying conductor, motion in a magnetic field and in electric and magnetic fields combined.

Further, you come to know about velocity selector and cyclotron; magnetic field due to a current element, magnetic field on the axis of a circular current loop, Biot-Savart law, Ampere’s circuital law, the solenoid and the toroid, force between two parallel currents, the Ampere, torque on a current loop, magnetic dipole, torque on a rectangular current loop in a uniform magnetic field, magnetic dipole in a circular current loop, the magnetic dipole moment of a revolving electron and the moving coil galvanometer. Here you will find 32 VSAQs, 56 SAQs and 15 LAQs to solve.

## Xam Idea Class 12 Physics Chapter 5 (Magnetism and Matter) Solutions

Chapter 5 of Xam Idea Class 12 Physics introduces you to the bar magnet and the magnetic field lines. Further, you learn about bar magnet as an equivalent solenoid, the dipole in a uniform magnetic field, the electrostatic analogue of magnetism and Gauss’s law. Next, you come to about the earth’s magnetism, magnetic declination and dip, magnetisation and magnetic intensity. You also study about magnetic properties of materials like diamagnetism, paramagnetism and ferromagnetism. This chapter has 28 VSAQs, 31 SAQs and 3 LAQs.

## Xam Idea Class 12 Physics Chapter 6 (Electromagnetic Induction) Solutions

Electromagnetic Induction chapter of Xam Idea Class 12 Physics discusses experiments of Faraday and Henry, magnetic flux and Faraday’s Law of induction. You also learn Lenz’s law and conservation of energy, motional electromotive force, energy consideration: a quantitative study. Further, you learn about Eddy currents, inductance, mutual inductance, self-inductance and ac generator. You need to solve 34 VSAQs, 33SAQs and 8 LAQs in this chapter.

## Xam Idea Class 12 Physics Chapter 7 (Alternating Current) Solutions

Alternating Current chapter teaches you about AC voltage applied to a resistor, representation of AC and voltage by rotating vectors, phasors and that when a value is given for ac voltage or current, it is ordinarily the RMS value. Next, you learn about AC voltage applied to an inductor, a capacitor and a series LCR circuit.

This chapter also teaches you that the power rating of an element used in AC circuits refers to its average power rating and there are no power losses associated with pure capacitances and pure inductances in an AC circuit. You also learn about phasor-diagram solution, analytical solution, resonance, LC oscillations and transformers. You will also be taught that a transformer (step-up) changes a low-voltage into a high-voltage. This chapter consists of 15 VSAQs, 50SAQs and 14 LAQs.

## Xam Idea Class 12 Physics Chapter 8 ( Electromagnetic Waves) Solutions

Electromagnetic Waves chapter of Xam Idea Class 12 Physics Book lets you know about the concept of displacement current, electromagnetic waves and the electromagnetic spectrum. You come to know about the RMS value of the conduction current and the similarities between conduction current and displacement current. Further, you learn about sources and nature of electromagnetic waves, frequency of electromagnetic waves produced by the oscillator, photo-energy of different parts of the electromagnetic spectrum and how to obtain different scales of photon energies of electromagnetic radiation.

Next, you learn about radio waves, microwaves, infrared waves, visible rays, ultraviolet rays, X-rays and gamma-rays in this chapter. There are 55 VSAQs and 31 SAQs in this chapter. Our Xam Idea Class 12 Physics Solutions answer all questions in detail.

## Xam Idea Class 12 Physics Chapter 9 (Ray Optics and Optical Instruments) Solutions

In this chapter first, you learn about the sign convention in the field of reflection by light. Further, you learn about the focal length of spherical mirrors, the mirror equation, refraction, total internal reflection, total internal reflection in nature and its technological applications.

Next, you learn about refraction at spherical surfaces and by lenses, refraction at a spherical surface, refraction by a lens, power of a lens, a combination of thin lenses in contact, refraction through a prism, dispersion by a prism, some natural phenomena due to sunlight, the rainbow scattering of light optical instruments, optical instruments, the eye, the microscope and the telescope.

You get to solve 35 VSAQs, 69 SAQs and 13 LAQs based on the above concepts. Our Xam Idea Class 12 Physics Solutions help give you ample amounts of practice and help you become thorough with the chapter.

## Xam Idea Class 12 Physics Chapter 10 (Wave Optics) Solutions

Wave Optics chapter of Xam Idea Class 12 Physics Solutions teaches you the derivation of laws of refraction and reflection using Huygens law. You also learn about refraction and reflection of plane waves using the Huygens principle. Next, you learn about refraction of a plane, wave refraction at a rarer medium, reflection of a plane wave by a plane surface, the doppler effect.

You also learn about the coherent and incoherent addition of waves, interference of light waves and Young’s experiment. This chapter also teaches you about diffraction, the single slit, seeing the single slit diffraction pattern, resolving power of optical instruments, polarisation, the validity of ray optics, and polarisation by scattering and reflection. There are 17 VSAQs, 36 SAQs and 14 LAQs in this chapter.

## Xam Idea Class 12 Physics Chapter 11 (Dual Nature of Matter and Radiation) Solutions

Chapter 11 tells you about electron emission and photoelectric effect and that the minimum energy needed by an electron to leave the metal surface is given the term work function of the metal. You further learn about the dual nature of radiation matter, Hertz’s observations, Hallwachs’ and Lenard’s observations. Next, you learn about the experimental study of photoelectric effect; effect of intensity of light on photocurrent, the effect of potential on photoelectric current and effect of frequency of incident radiation on stopping potential. You also learn about the photoelectric effect and wave theory of light.

You also learn that in the event of matter-light interaction, absorption of energy takes place in discrete units of  and you learn about Einstein’s photoelectric equation, energy quantum of radiation, particle nature of light: the photon and wave nature of matter. There are 47 VSAQs, 57 SAQs and 3 LAQs based on the above concepts.

## Xam Idea Class 12 Physics Chapter 12 (Atoms) Solutions

The 12th chapter of Xam Idea Class 12 Physics tells you that everything in our universe is made up of atoms which is the fundamental building block of all matter. Further, this chapter teaches you about alpha-particle scattering and Rutherford’s nuclear model of the atom — where an atom is described to have a minute, dense, positively charged core called nucleus surrounded by negatively charged constituents called electrons.

Further, you learn about alpha-particle trajectory, electron orbits, atomic spectra, spectral series, Bohr model of the hydrogen atom, energy levels, the line spectra of the hydrogen atom, de Broglie’s explanation and Bohr’s second postulate of quantisation. You can practise with 11 VSAQs, 30 SAQs and 3 LAQs given in this chapter.

## Xam Idea Class 12 Physics Chapter 13 (Nuclei) Solutions

This chapter tells you all about atomic masses and composition of the nucleus, size of the nucleus, mass-energy and nuclear binding energy, nuclear force. You also learn about the phenomena of radioactivity, the law of radioactive decay and types of decay like alpha decay, beta decay, gamma decay. It further teaches about nuclear energy, fission, nuclear reactor, nuclear fusion – energy generation in stars and controlled thermonuclear fusion. You can find 24 VSAQs, 40 SAQs and 7 LAQs in this chapter.

## Xam Idea Class 12 Physics Chapter 14 (Electronic Devices) Solutions

Electronics Devices chapter of Xam Idea Class 12 Physics book first tells you about the classification of metals, conductors and semiconductors. Further, it teaches about intrinsic semiconductor, extrinsic semiconductor, p-n junction, p-n junction formation, semiconductor diode, p-n junction diode under forwarding bias, p-n junction diode under reverse bias, application of junction diode as a rectifier, special purpose of p-n junction diodes, Zener diode, optoelectronic junction devices.

Next, you learn about junction transistor, transistor: structure and action, basic transistor circuit configurations and transistor characteristics, transistor as a device, transistor as an amplifier, feedback amplifier. You also come to know about transistor oscillators, digital electronics and logic gates, logic gates, integrated circuits. You learn how to calculate output frequency of a half-wave and full-wave rectifier, find the number of holes and electrons in atoms of silicon, Indium and arsenic, calculate the ratio between conductivity at two different temperatures and solve problems related to OR, AND and NAND gates. You can practise all the above concepts with 50 VSAQs, 59 SAQs and 16 LAQs.

## Xam Idea Class 12 Physics Chapter 15 (Communication Systems) Solutions

The last chapter of Xam Idea Class 12 Physics book tells you everything about the elements of a Communication system. Communication systems are a collection of systems used for transmission, interconnection and communication. You learn all about modern era methods like e-mail, internet, television, radio and computer. You will study the basic terminology used in electronic communication systems, the bandwidth of signals and transmission medium.

Next, you will learn about the propagation of electromagnetic waves, ground waves, skywaves and space waves. Further, you learn about modulation and its necessity, size of the antenna or aerial, effective power radiated by an antenna, mixing up of signals from different transmitters, amplitude modulation, production of amplitude modulated waves, detection of the amplitude-modulated wave. This chapter contains 41 VSAQs, 45 SAQs and 3 LAQs for practice.