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1.         Magnetic field is a vector i.e. having magnitude & direction.
2.         A compass needle is used to detect magnetic field & find its direction.
3.         Like magnetic poles repel each other & unlike magnetic poles attract each other.
4.         Magnetism produced in an electric crane is temporary i.e. as long as the current  flows.
5.         No two magnetic lines of force can intersect each other.
6.         Oersted experiment – where there is no current in the wire, the magnetic needle is at rest along the north south direction.
7.         Solenoid is a coil of many turns of insulated Cu. wire wraped  in a shape of cylinder.
8.         Permanent magnets are made from hard steel, carbon steel, chromium, cobalt & tungsten steel, Alnico & nipermag etc.
9.         Alnico is the alloy of aluminium nickel, cobalt, iron.
10.       Nipermag is the alloy of iron, nickel, aluminium & titanium.
11.       Permanent magnets are used in loudspeaker, a microphone electricclock, a speedometer, a galvanometer, an ammeter, avoltmeter etc.
12.       MRI- Magnetic. Resonance imaging technique is used to obtain the images of different body parts.
13.       Electric motor converts electrical energy into mechanical energy.
14.       Electromagnetic induction was discovered by Michael Faraday in (1832) & independtly by Joseph Henry in (1830)
15.       Galvanometer is an instrument used to detect the presence of current in a circuit.
16.       D.C. flows only in one direction. Frequency is zero.
17.       A.C. changes direction reverses periodically with time.
18.       Frequency is 50 Hz is used in electric heater, refrigerator.
19.       State electricity board provides i) phase wire (live wire). ii) neutral wire & iii) the earth wire for houses & factories.
20.       P.D. between live wire & neutral wire is 220V – 250V.
21.       The main fuse is connected to live wire (phase wire.)
22.       The system connecting metal casing of electrical appliance to a Cu plate buried deep inside the earth is Earthing.
23.       Lightning involves very high P.D. & electric field, so switch off electrical appliances.
24.       Electromagnet & soft iron strip are the component of electric bell.
25.       Electric motor converts electrical energy into mechanical energy.
26.       Electric generator converts mechanical energy into electrical energy.
27.       When a live wire & a neutral wire came in contact or touch each other results into short circuit.

28.       In Latin ‘Acidus’ means, sour.
29.     Litmus paper or solution is obtained from lichen a plant.
30.     Natural indicators- natural substances rose petals, turmeric, beet root, etc.
31.      Litmus paper strips are ordinary blotting papers soaked in a litmus solution & then dried.
32.     Litmus papers are handy due to dry & light in weight.
33.     Synthetic indicators- chemic substances- phenolphthalein, methyl orange, eosin etc.
34.     Red ants are known as forma in Greek – having formic acid.
35.     pH stands for potenz (strength). indicating acidic or basic nature of solution.
36.     Human body works within 7.35 to 7.45 pH range.
37.     Hydrochloric acid produced in stomoch helps in digestion of food.
38.     Antacid are basic substances which controls the acidityd indigestion problems.
39.     Acid reacts with base to form salt & water is the Neutralization
40.     HA + BOH  ----->    BA + H2O
          Hydronium ion (H3O+)
41.     Impure NaCl is brown in colour known as rock salt.
42.     Pure NaCl is colourless, crystalline ionic compound to forms other salts like Na2CO3 & NaHCO3 etc.
43.     Sodium bicarbonate (NaHCO3)- baking soda alkaline in nature.
44.     NaHCO3 is used for the production of CO2 which is one of the constituents in fire extinguishers.
45.     Bleaching powder CaOCl2 chloride of lime oxidising agent; used in the preparation of chloroform(Anaesthetic)
46.     Na2CO3  is sodium carbonate commonly called washing soda.
47.     Crystalline substances that have lost their water of crystallization are called anhydrous (without water)
48.     Anhydrous substances form coloured solutions when they are added to water.
49.     Soap are the sodium or potassium salt of carboxylic acids.
50.     Saponification is the alkaline hydrolysis of soap.
51.     Water glass is prepared by fusing a mixture of sand & washing soda.
52.     Toothpaste (pH about 8.0) contains fluorides & bases to neutralize the mouth acid.
53.     Sodium bicarbonate (NaHCO3) is used as an antacid in medicine.
                             

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