NCERT Physics and Science Practice Answers Review

Comprehensive Answer Key for Science Chapters 1 Through 8

The fundamental concepts covered in the initial chapters are represented by a series of multiple-choice and short-answer solutions. For Chapter 1, the answers are provided for three questions: item 1 is (i), item 2 is (d), and item 3 is (a). Chapter 2 contains solutions for four items where question 1 is (d), question 2 is (b), question 3 is (d), and question 4 is (c). In Chapter 3, the responses are marked as 1 (d), 2 (c), 3 (a), and 4 (c). For Chapter 4, the correct options are specified as 1 (b), 2 (c), and 3 (b).

Continuing through the core science curriculum, Chapter 5 identifies solutions as 1 (c), 2 (a), 3 (d), and 4 (b). Chapter 6 comprises three indexed answers: 1 (d), 2 (b), and 3 (d). Chapter 7 follows with answers 1 (b), 2 (c), and 3 (d). Chapter 8 is noted with a single response for question 1, which is option (c). These solutions correspond to the material found in the science textbook marked for the Reprint 2026-27.

Advanced Analysis of Light: Reflection and Refraction (Chapter 9)

Chapter 9 provides detailed solutions regarding optical phenomena, including reflection and refraction. The multiple-choice section identifies the following correct options: 1 (d), 2 (d), 3 (b), 4 (a), 5 (d), and 6 (c). Beyond multiple-choice items, the text provides qualitative and quantitative assessments. Question 7 specifies that for an object, the distance must be less than $15\,cm$ to produce a virtual and enlarged image. Question 9 simply indicates an affirmative "Yes".

Numerical problems within Chapter 9 offer specific values for image characteristics and mirror/lens properties. Question 10 states that an image is formed at a distance of $16.7\,cm$ from the lens on the opposite side; the image size is $3.3\,cm$, and it is classified as reduced, real, and inverted. Question 11 notes a value of $30\,cm$. Question 12 determines the image position to be $6.0\,cm$ behind the mirror, which is virtual and erect.

In question 13, the magnification factor $m = 1$ is explained as an indication that the image formed by a plane mirror is of the exact same size as the object. The positive sign associated with magnification $m$ further indicates that the image is virtual and erect. Question 14 describes an image located $8.6\,cm$ behind the mirror, which is virtual, erect, and has a reduced size of $2.2\,cm$. Question 15 identifies an image position of $54\,cm$ on the object side, characterized as magnified, real, and inverted with a size of $14\,cm$. Finally, questions 16 and 17 provide focal lengths and lens types: question 16 identifies a focal length of $-0.50\,m$ associated with a concave lens, while question 17 identifies $+0.67\,m$ for a converging lens.

Optical Principles and Corrective Vision (Chapter 10)

Chapter 10 continues the study of optics with a focus on vision and human biological interfaces. The initial set of questions lists the answers as 1 (b), 2 (d), 3 (c), and 4 (c). For question 5, two specific values are provided: (i) $-0.18\,m$ and (ii) $+0.67\,m$. Question 6 identifies the requirement for a concave lens with a power of $-1.25\,D$. Question 7 specifies the use of a convex lens with a power of $+3.0\,D$. This chapter reflects the technical standards of the Reprint 2026-27 material.

Theoretical and Practical Principles of Electricity (Chapter 11)

Chapter 11 addresses the complex calculations and theoretical foundations of electrical circuits. The multiple-choice answers are 1 (d), 2 (b), 3 (d), and 4 (c). Theoretical questions include question 5, which answers "Parallel", and question 6, which provides a length of $122.7\,m$ and a relative change of $\frac{1}{4}$ times. Resistance values are recorded for question 7 as $3.33\,\Omega$ and for question 8 as $4.8\,k\Omega$. Question 9 identifies a current value of $0.67\,A$.

Specific electrical requirements and component counts are detailed in several questions. Question 10 requires the use of $4$ resistors, while question 12 calculates a total of $110$ bulbs. Question 13 provides three distinct current values: $9.2\,A$, $4.6\,A$, and $18.3\,A$. Question 14 evaluates power consumption, finding $8\,W$ for both sub-items (i) and (ii). Question 15 determines a current of $0.73\,A$. In question 16, a comparison of energy consumption identifies a $250\,W$ TV set operating for $1$ hour as significant. Question 17 lists a power rating of $1100\,W$. Question 18 provides theoretical explanations, noting the high resistivity of alloys in part (b) and that values vary inversely in part (d).

Magnetic Effects and Environmental Science (Chapters 12 and 13)

Chapter 12 covers the magnetic effects of electric current through various identifying answers. Questions 1 and 2 are (d) and (c), respectively. Question 3 contains True/False evaluations where (a) is True and (b) is False. Question 6 describes a direction as vertically downwards. For question 7, foundational physical rules are named: part (i) refers to the Right-hand thumb rule, and part (ii) refers to Fleming’s left-hand rule. Chapter 13, which concludes the curriculum sequence, provides the following answers: question 1 comprises (a), (c), and (d); question 2 is (b); and question 3 is (d). These documents are part of the NCERT reprint for 2026-27.