SCIENCE - STD. 10th (LAWS)

 

Ohm’s Law – The Potential Difference across the ends of resistor is directly proportional to the current flowing through it, provided its temperature remains the same.              

Joule’s Law of Heating – The Heat produced in a resistor is directly proportional to the (i) square of the current for a given resistance (ii) resistance of a given current and (iii) .the time for which current flows through the resistor

H = I²Rt

 Laws of Reflection – i) The Angle of Incidence is equal to the angle of reflection.

ii) The incident ray, reflected ray and the normal, all lie in the same plane.

 Laws of Refraction – i) The incident ray, the refracted ray and the normal to the interface of the two transparent media at the point of  incidence, all lie in the same plane. ii) The ratio of the Sine of angle of incidence to the Sine of angle of Refraction is constant . (This is also known as Snell's Law)

Right Hand Thumb Rule – Imagine that you are holding a current carrying straight conductor in your right hand such that the thumb points towards the direction of the current, then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field.

 Fleming’s Right Hand Rule – Stretch the thumb, forefinger and middle finger of your left hand such that they are perpendicular to each other. If the fore finger indicates the direction of the magnetic field and the thumb shows the direction of motion of the conductor, then the middle finger shows the direction of induced current.

 Fleming’s Left Hand Rule – Stretch the thumb, forefinger and middle finger of your left hand such that they mutually are perpendicular. If the first finger points the direction of the magnetic field and the second finger in the direction of the current, then the thumb will point in the direction of motion or the force acting on the conductor.

 Dobereiner Law of Triad – This Law states that when the three elements having similar properties are arranged in the increasing order of their atomic masses, the atomic mass of the middle element is approximately the mean of the atomic mass of the other two elements.

 Newland’s Law of Octaves – This law states that when the element are arranged in the increasing order of their atomic mass, every eighth element has similar properties to first one.

 Mendeleev Periodic Law – The properties of the elements are the periodic functions of their atomic mass.

 Modern Periodic Law – The properties of elements are the periodic functions of their atomic number.