Category: Selina ICSE Solutions

Exercise Q1. Fill in the blanks.(a) Dalton _ that atoms could not be divided(b) An ion which has a positive charge is called a _.(c) The outermost shell of an atom is known as _.(d) The _ of an atom is very hard and dense.(e) Neutrons are _ particles having mass equal to that of […]

Exercise-4A Question 1. What do you understand by refraction of light?Solution:Refraction of light refers to the shift in the direction of the light’s path when it moves from one transparent material to another. Question 2. Draw diagrams to show the refraction of light from(i) Air to glass in diagram, label the incident ray, refracted ray, and the […]

Exercise-11A Question 1. Define the term heat.Solution:The thermal energy of a material is the kinetic energy brought on by the random motion of its molecules. Question 2. Name the S.I. unit of heat.Solution:Joule is the S.I. unit of heat (symbol J). Question 3. Define the term calorie. How is it related to joule (the S.I. unit of heat)?Solution:The […]

Exercise-10A Question 1. Describe an experiment to demonstrate that there is a magnetic field around a current-carrying conductor.Solution:In Fig., AB is represented as a wire that runs from north to south and is linked to a battery via a rheostat and a tapping key. The wire is positioned right below a compass needle.(1) The needle does […]

Exercise 2(A) Question 1. Define work. Is work a scalar or a vector?Solution:Only when a body moves as a result of a force being applied to it is stated to have been done. It’s a scalar amount. Question 2. How is the work done by a force measured when:1. the force is in direction of displacement2. the […]

Question 1. (1) What do you understand by a simple machine?(2) State the principle of an ideal machine.Solution:(1) A machine is a tool that allows us to increase speed or overcome a strong resistive force by exerting a modest force at a suitable location and in the desired direction.(2) A perfect machine is one that has […]

Exercise-7a Question 1. What are mechanical waves?Solution:The waves that need a material medium to transmit energy are known as mechanical waves. Question 2. (i) Define amplitude term in relation to a wave.(ii) Define frequency term in relation to a wave.(iii) Define wavelength term in relation to a wave.(iv) Define wave velocity term in relation to a wave.Solution:(i) […]

Exercise-5a Question 1. What is a lens?Solution:A lens is a transparent refracting medium that is surrounded by two usually spherical curved surfaces. Question 2. Name the different kinds of lenses. Draw diagrams to illustrate them.Solution:There are two types of lens: –(i) Convex or converging lens,(ii) Concave or diverging lens. Question 3. State two differences between a convex and […]

Question 1. Name three factors on which the deviation produces by a prism depends and state how does it depend on the factors stated by you.Solution:The deviation produced by the prism depends on the following four factors:(a) The angle of incidence – As the angle of incidence rises, the angle of deviation initially falls and, for […]

EXERCISE-8A Question 1. Define the term current and state its S.I unit.Solution:The speed at which charges flow is known as current.I=q/t Question 2. Define the term electric potential. State its S.I. unit.Solution:Potential at a point is the effort put in to move a unit positive charge there from infinity. Volt is a SI unit, with 1 V […]