What Is The Normal ForceThe external agent which tends to set a body in motion or which changes the speed and direction of motion of a body or which can change the shape of a body is called force. SI unit of force is Newton.Types of Forces: (a) Non Cont…

HEAT – A FORM OF ENERGYHave you stirred hot tea or milk with a stainless steel spoon? Next time you do this, leave the spoon in the hot liquid for a little while. Now, touch the handle of the spoon. What do you notice? The handle of the spoon would have…

Image Formation By Convex Lens in Different CasesCase 1: Object at Infinity A point object lying on the principal axis: Rays come parallel to the principal axis and after refraction from the lens, actually meet at the second principal focus F2. Fig. Co…

How Do You Measure Density\(\text{Density}=\frac{\text{Mass}}{\text{Volume}}\text{    or   d}=\frac{\text{M}}{\text{V}}\)SI unit of density is kg/m3 and CGS unit of density is g /cm31 gm/cm3 = 1000 kg/m3Different substances have different densities whic…

Mirror Image Of Coordinates Of A PointWith respect to x axis: In image of a point P(x, y) with respect to x axis, the change in only sign of ordinate of point so the image is Q(x, –y). P1 (–3, 1) & P2 (5, –2) are two points in II & IV quadrant r…

What is an electric field and how is it created?An electric field is a region in which an electric charge experiences an electric force.Figure shows an electric field created by a positively-charged sphere. Such a field can be represented by a number of …

Analysing Reflection of WavesFigure shows the reflection of sea waves by a retaining wall built near the beach. Reflection of waves is a phenomenon that occurs when all or a part of the waves return after they encounter an obstacle. The obstacle is know…

What is the Relationship between Electric Current and Potential Difference?When an electric charge is placed at a point in an electric field, it experiences an electric force acting on it. Work is required to move the electric charge in the electric fiel…

What is the Law of Reflection of Light?First law : The incident ray, the reflected ray and the normal at the point of incidence, all lie in the same plane.Second law : The angle of reflection (∠r) is always equal to the angle of incidence (∠i). i.e.,   …

What does Boyle’s Law state? Figure shows an air pillow. When the boy puts his head on the pillow, the air in the pillow is compressed. The pressure of the air increases to support his head. Boyle’s law gives the relationship between the pressure and the…