151) Shearing strain = 2 x longitudinal strain
152) Bulk strain = 3
x Longitudinal strain
153) Annealing : means slow cooling after heating .
Annealing reduces elastic property of the body.
154) If temp increases generally the elastic property of
body decreases.
155) In case of rubber , the modulus of elasticity increases
with increase in temperature.
156) Elasticity of a perfectly rigid body is infinite.
157) For liquids and gases young’s modulus (Y) and rigidty
modulus(ƞ)
do not exist.
158) Gases are least elastic as they are most compressible.
159) Poisson’s ratio lies between -1 and 0.5. but in actual
practise it lies between 0 and 0.5.
160) For most of solids ‘σ’ lies between 0.2 and 0.4.
161) ‘σ’ for rubber is nearly 0.5
162) For incompressible liquids Bulk modulus is infinite and
poisson’s ratio is 0.5
163)The pressure inside a bubble or liquid drop is greater than
the outside pressure. This excess pressure is inversely proportional to radius
of bubble.
164)Pressure inside a smaller bubble is greater than the pressure
inside a larger bubble or drop.
165)A sphere has minimum surface area for given volume.
166)When a bigger drop splits into smaller drops energy is
absorbed.
167) When a smaller drops merge to form a larger drop , energy is absorbed.
168) A water proofing agent changes angle of contact from an acute
to obtuse value.
169) Meniscus of mercury in capillary is convex.
170) When a soap bubble is charged it expands.
171) Viscocity of liquids increases with increase of pressure.
172)Venturimeter is the device to measure rate of flow of liquid
through a pipe.
173) In winter as temperature falls , viscocity of lubricants
increases so machine parts will be jammed during winter.
174) Principle behind working of Gas burner is Bernouli’s
principle.
175) A rifle bullet is cylindrical so that it doesn’t experience
any dynamic lift.
176) Rain drops falling from high clouds reach the earth with
uniform velocity but different for different sizes.
177) The coefficient of Viscocity is highest for water.
178) Good lubricant should have high viscocity.
179) Clouds float In atmosphere because of their low viscocity.
180) Equation of continuity is law of conservation of mass.
181) Invar steel—64% steel; 36% nickel.
182) Coefficient of linear expansion of rubber is negative .
183) A bimetallic strip consists of copper and steel strips.
184) Water has ananalous expansion due to formation of more no. of
hydrogen bonds.
185) ”Diatometer “ is used to study the anamolous expansion of
water.
186) Soft rubber also exhibits anamolous expansion.
187) At 0 oC, the coefficient of expansion of water is zero.
188) Water has minimum volume and maximum density at 4o C or 277 K
189) If an air bubble raises from bottom to surface of a lake then
its volume increases
190) The gas thermometers are more sensitive than liquid
thermometers because gases expand more than liquids.
191) Triple point of water is 0.01 oC
192) Triple point of CO₂ is 216.65 K at 3.8mm of Hg
193) Triple point of Iodine is 387 K at 90mm of Hg.
194) Ice at 0o C produces more cooling than water at 0 oC.
195) At boiling point specific heat of water is infinite.
196) Entropy during change of phase may increases or decrease.
197) Specific heat of gas in isothermal process is Infinity.
198) A block of ice can radiate energy.
199) The waves produced during earth quakes are infrasonics.
200) Sound travels in rocks in the form of both longitudinal and transverse elastic waves.
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