1km= 103 m or 1kg=103g
1mm=10-3m or 1mg=10-3g
Quantity & Units:
Speed meter/sec
Acceleration meter/sec2
Resistance ohm
Charge coulomb C
Pressure Pascal
Force Newton
Torque Newton/meter2
Area Meter 2
Volume cubic meter
Current Ampere
Power watt
Momentum Newton. Second
Scalar Quantities:
Those physical quantities which are measured only by their magnitude, called scalar quantities e.g. 25 liter petrol.
Vector Quantities:
Those physical quantities which are measured not only for their magnitude but their direction as well for their complete description, called vector quantities
Speed:
The distance covered by a body per unit time, called speed.
4. Velocity:
The distance covered by a body per unit time but in a specific direction, called velocity.
5. Mass:
The quantity of matter present in a body, called mass.
6. Weight:
Weight is the force with which the earth attracts the body towards it center, called weight. W=mg
Ammeter:
A device which is used to measured the current, called ammeter.
Voltmeter:
A device which is used to measured the voltage or potential difference v, called voltmeter
Machine:
A device which helps us to do work more conveniently, called machine.
kinds of Machines:
Lever, pulley, wheel & axels, inclined plane, screw etc.
Barometer:
A device which is used to measured the atmospheric pressure, called barometer.
Newton first law of motion / Inertia:
Every object continuous it state of rest or in uniform motion in a straight line unless it is acted upon by some external force, called Inertia.
Newton 3rd law:
For every action there is always equal but opposite in direction, called Newton 3rd law.
Efficiency:
Efficiency =output of the machine / input of the machine
Torque:
Turning effect of force is called torque
Torque = Force * moment arm
Atomic No:
The total numbers of proton & electrons in the nucleus of an atom, called atomic no.
17. Atomic Mass:
The total number of protons & neutrons in the nucleus of an atom, called atomic mass.
18. Friction:
That force which resists the motion of a body, called friction.
With out friction between our legs and ground we will able to move on.
Due to friction heat is produced and causes burning.
19. Momentum:
It is the product of mass and velocity, momentum will be increased with the increased of mass of the moving body as well momentum will be increased with the increase in velocity of the body.
P=Mv Newton. Second (Unit)
20. Law of conservation of Momentum:
The momentum of an isolated system remains constant
“Isolated system means a system where no external force exerted”
21. Newton 2nd law of Motion:
When a force acts on a body it produces acceleration in its own direction, which is directly proportional to the force and inversely proportially to the mass of the body i.e.
F=ma
22. Distance:
The change of position of a body, called distance.
23. Displacement:
The change of position of a body but in a particular direction, called displacement.
24. Radar:
Radar is used for the purpose of locating and identifying the objects, which can’t be seen by eyes or telescope. It is used for military purpose, for air traffic control, for weather observation as well for storm warning.
25. Center of gravity:
Center of gravity is the point where the whole weight of the body appears to act.
26. Matter:
Matter is made up of small particles, called molecules. Molecules are made up of one or two atoms. Matter exists in three state i.e. solid, liquid & gas. Temperature and pressure change the state of matter.
Law of Universal Gravitation:
Every object in the universe attracts every other object with some force that is called law of universal gravitation.
28. Types of Equilibrium:
Stable Equilibrium: A Moving car or Book lying on a table.
Unstable Equilibrium: A pencil is standing on a table for a moment
Neutral Equilibrium. When center of gravity is below the point of suspension
29. Audible Frequency:
A frequency of sound waves that can be detected by human ear easily, called audible frequency. The average range of audible frequency is 20 HZ to 20000 HZ.
30. Evaporation:
Changing of liquid into vapour with out being boiling, called evaporation
Drying cloth is the best example of it
31. Frequency:
The number of vibration in one second, called frequency.
F=I / T
32. Time period:
Time required completing one vibration or one complete trip, called time period.
33. Concave lens:
It is thinner at the center and thicker at the edges. It diverges the beam of light.
Uses: head light of automobiles, microscope, searching lights as well medical check-up for air, nose etc khy liye bhi used hota hai.
BECAUSE IT GIVES REAL AND VIRTUAL VIEW
34. Convex lens:
It is thicker at the center at thinner at the edges. It converge the beam of light.
Uses: Narrow turning, security purpose, to see the lower part of vehicles
BECAUSE IT GIVES REAR VIEW
E=MC2
According to this mass can be converted in energy and energy can be converted in mass, it is explained by Einstein.
Current:
The flow of charges in a conductor is called current.
37. Conductor:
The substance which transfer heat and electricity, called conductor.
38. Resistance:
The substances which opposes the flow of charges, called resistance
39. Nuclear-Fission;
Nuclear fission is the process in which a heavy nucleus spilt up into two smaller fragments with an evolution of huge amount of energy, called nuclear fission.
40. Nuclear Fusion:
Nuclear fusion is the process in which two light nuclei fused to form up a bigger nucleus with an evolution of huge amount of energy, called nuclear fusion.
41. Ohm’s law:
The current passing through a conductor is directly proportional to the potential difference V applied across the terminal of the conductor provided temperature and other physical conditions remain constant.
42. Capacitor:
A device which is used for storing electric current called Capacitor.
43. Coulomb’s Law:
An electrostatic attractive or repulsive force between two point charges is directly proportional to the product of the magnitude of the charges and inversely proportional to the square of the distance between them.
44. Pressure:
Pressure is the force per unit area. Pressure has a direct relation with force and has inverse relation with area.
P=f / A
45. Barometer:
Barometer is a device which is used for measuring atmospheric pressure.
46. Pascal Law:
The pressure applied to any place to an enclosed fluid is transmitted equally and undimensionally to every portion of the fluid.
47. Buoyancy:
Buoyancy is the force with which a liquid pushes an object upward, when it is lowered in liquid..
48. Hook’s law:
Under the elastic limit stress is directly proportional to strain.
Stress*strain
49. Archimedes principal:
When an object is immersed in liquid, an up thrust acts upon it which is equal to the weight of the liquid displaced by the object.
50. Speed of light & Speed of Sound:
Speed of sound in air at O C is 330 m/s
Speed of light is 3*108 m/s
51. Centripetal Force:
The force which is responsible to keep the body moving in a circular path and it is directed towards the center of the circular path is called centripetal force.
52. Centrifugal Force:
The force which is responsible to keep the body moving in a circular path and it is directed away from the center of the circular path.
53. Mechanical advantage:
It is a ratio between load and effort.
M.A = Load / Effort
54. Mechanical Advantage of Lever:
Mechanical advantage of lever can be increased by increasing the effort arm as compared to weight arm.
55. Transfer of heat:
There are three processes by which heat energy is transferred from one place to another. 1conduction 2 radiation 3 convection
Conduction: In this mode heat energy is transferred from atom to atom or molecule to molecule with out the movement of substances or mass from one position to another.
Convection: In this mode heat energy is transferred from one place to another place by means of movement of atom or molecules.
Radiation: In this mode no medium, is required as in convection and radiation. When these radiations fall on the object they transfer energy to the body.
56. Echo:
The sound heard after reflecting from the surface is called Echo.
57. Wavelength:
It is a horizontal distance covered by a wave in one complete cycle.
58. Amplitude:
It is a maximum vertical distance covered by a wave from it normal.
59. Ultrasonic and subsonic:
Waves having the frequency above the audible range, called ultrasonic and waves having frequency below the audible range, called subsonic.
60. Dispersion of light:
When a light fall on a prism, the light split up into seven colors. This phenomenon is called dispersion of light.
61. Refraction of light:
When a light ray is traveling from one medium to another medium and changes it path, this phenomenon is called refraction of light
When a rays of light traveling from rarer medium to denser medium it will bend toward the normal.
When a rays of light traveling from denser medium to rarer medium it will bend away from the normal..
62. Law of Reflection:
The reflection of ligth occurs in two laws according to Muslim scientist Ibn-al-haitham.
The angle of incidence is equal to the angel of reflection.
The incident ray,, reflected ray and normal lie in the same plane
63. Doppler Effect:
It is the apparent change in frequency of wave to the observer moving relative to it source.
63. Reflection of light:
Bouncing back of a light ray after hitting any surface is known as reflection
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