In a cyclic quadrilateral ABCD; a, b, c, d denote the length of the sides AB, BC, CD, and DA respectively. Then cos A is equal to
(1) (a2 + d2 – b2 – c2)/2(ad + bc) (2) (a2 + d2 – b2 – c2)/2(ab – dc)... View Article
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If the angles of a triangle are in the ratio 1 : 3: 5 and θ denotes the smallest angle, then the ratio of the largest side to the smallest side of the triangle is
(1) (√3 sin θ + cos θ)/2 sin θ (2) (√3 cos θ – sin θ)/2 sin θ (3) (... View Article
In a triangle ABC, if c = (a – b) sec θ, then tan θ is equal to
(1) 2 [√(ab)/(a – b) ] sin (C/2) (2) 2 [√(ab)/(a – b) ] tan (C/2) (3) 2 [√(ab)/(a –... View Article
In a triangle ABC, the median AD is perpendicular to AC. If b = 5 and c = 11, then a is equal to
1) 10 2) 12 3) 14 4) √221 Solution: Given b = 5 and c = 11 We have cos... View Article
If in a triangle sin A/sin C = sin (A – B)/sin (B – C), then
(1) sin2 A, sin2 B, sin2 C are in GP (2) sin 2A, sin 2B, sin 2C are in AP... View Article
If the angles A and B of the triangle ABC satisfy the equation sin A + sin B = √3(cos B – cos A), then they differ by
(1) π/6 (2) π/3 (3) π/4 (4) π/2 Solution: Given sin A + sin B = √3(cos B – cos... View Article
The circumradius of the triangle whose sides are 13, 12, and 5 is
1) 15 2) 13/2 3) 15/2 4) 6 Solution: Let a = 13, b = 12 and c = 5... View Article
What is a monomer in plastic
Plastics are made from many identical small particles called monomers. These monomers are strung together like a chain to form... View Article
Which is the best definition of a wave?
Wave is a disturbance in which there is a transfer of energy from place to place. The particles of the... View Article
How is fructose a reducing sugar
Fructose is a reducing sugar. All the monosaccharides are reducing sugars. Fructose is a monosaccharide with a ketone group.
What is the difference between Sulphur and sulphide?
Sulphur is a chemical compound with the symbol S and has the atomic number 16. Sulphide is an inorganic anion... View Article
Does phenol give Friedel Crafts reaction?
Phenol can undergo Friedel Crafts alkylation. For Friedel Crafts acylation, harsher conditions like higher temperature are required.
How strong is the strongest acid
The strongest superacid in the world is Fluoroantimonic Acid. It is prepared by mixing hydrogen fluoride and antimony pentafluoride. A... View Article
What is the volume in PV=nRT
The ideal gas law is written as PV=nRT P is the pressure of the gas V is the volume of... View Article
How do you know which bond is stronger
The strength of the covalent bond can be determined by measuring the energy required to break the bond. The strength... View Article
Which has maximum covalent character
FeCl2 SnCl2 AlCl3 MgCl2 Answer: c) AlCl3 Reason As the cation charge increases the covalent character also increases. Al has... View Article
What is silica in food?
Silica or silicon dioxide is naturally present in some foods like beets, bell peppers, oats etc. It is also added... View Article
What is the fastest thing in the universe?
The fastest thing in the universe is the speed of light in vacuum. Nothing travels faster than the speed of... View Article
Which lens is used by the dentist?
Dentists do not use a lens, they use a concave mirror. The concave mirrors give a larger image of the... View Article
What Colour is oxygen
Oxygen gas is colourless, odourless and tasteless. The liquid and the solid form of oxygen is pale blue in colour
