Physics Facts Part 3

103. What is a drying agent?

A substance which makes the paint to dry quickly.

104. What is a drill? 

A tool used in making holes. illo ali deuord

105. What is Duralumin? 

It is an alloy of aluminium, copper, magnesium and silicon. It is stronger than aluminium.

106. What is hydrodynamics?

The study of forces of water and liquids.

107. What is aerodynamics.?

The study of the forces of air.

108. What is E.M.F.( Electron Motive Force)

Force generated by electric current in a magnetic field.

109. What are eddy currents?

The current of electricity induced at an undesirable place causing waste of energy.

110. What is Edison effect?

The conducting of electricity from an incandescent (bright hot) wire to a cold plate in the same container, as in a radio valve

111. What is an effervescent liquid?

Liquid in which gas is being formed as in coke.

112. What is an effluent?

Any gas or liquid produced in a processing unit.

113. What is elasticity?

The property of any material to spring to its original shape and size after releasing the external pressure.

114. What is electrochemical equivalent?

The weight of a substance deposited by the certain substance by passing one columb of electricity.

115. What is an electrolyte?

The liquid in which electricity can flow.

116. What is electrolytic copper?

A very pure copper obtained by electrolysis.

117. What is electrolysis?

The process of purifying a metal by passing a current through its solution.eg. when current is passed in a battery containing Copper sulphate, pure copper is deposited on the cathode.

118. What is an Electromagnet?

A bar of iron in the center of a coil of wire. When current is passed through the wire the iron bar gets magnetized.

119. What is electromagnetic induction?

The technique of producing a voltage in a circuit by changing the magnetic field around the circuit.

120. What is Electro motive force?

The force by which electricity flows in a circuit.

121. What are electromagnetic waves?

The electric energy traveling in space, as in radio waves, light waves etc.

122. What is electroplating?

It is the process of covering the surface of any material by a metal by the process of El ectrolysis.

123. What is an endothermic reaction?

A a reaction where heat is required for completion of the reaction.

124. What are epoxy resins?

Epoxy resins are formed from long chain molecular structure, especially vinyl ester with reactive sites at either ends. In the epoxy resin, however these reactive sites are formed by epoxy group. Epoxy refers to a chemical group, Its consisting of an oxygen atom bonded with two carbon atoms that are already bonded in other ways.

Epoxies find use as adhesives and laminating resins in variety of industrial applications.

125. What is an exothermic process?

A process in which heat is given out as the result of a reaction.

126. It is the unit to measure depth of a sea?

Fathom.

127. What is meant by fatigue of a metal?

Breaking of a metal after it has been subjected to external pressure. It is due to development and enlargement of surface cracks.

128. What are fish plates?

Plates fixed on either side of the railway track to hold them together.

129. What is magnetic flux?

The total amount of magnetic power passing through an area, e.g through the coil of an electric generator.

130. What is flux density?

It is the lines of force from the magnet that are present in the air. If an iron bar is placed near it the lines become concentrated near the iron bar, and the flux density becomes more near the iron bar.

131. What is the unit of flux density?

Flux density is measured by the number of induction lines which pass through one square centimeter area at right angles and the unit is gauss.

132. What is fly ash?

The very fine ash collected after burning coal in thermal stations.

133. What is meant by focusing a beam of light?

When a beam of light is made to pass through one single point, then it is said to be focused.

134. What are lines of force?

The forces in a magnetic or electrical field are represented by lines of force.

135. What is forging?

The process by which a hot metal is hammered and pressed to attain a particular shape.

136. What are fossil fuels?

The fuel, such as coal and oil, which is formed from the remains of animals and plants buried for years under the earth.

137. What is a foundry?

icon The place where metals are melted and cast to obtain different shapes.

138. What is the process of fractional crystallization ?

This is a process in which different solids are dissolved in water and separated from each other by crystallizing them at different temperatures.

139. What is fractional distillation?

This is a process of separating liquids with different boiling points. This is the process for separating the variousproducts of natural oils into various products like petrol, diesel etc. The vapours of these products are then condensed to form various liquids in a fractionating column.

140. What are Fraunhaofer lines?

These are dark lines in the spectrum of the sun the absorption of cooler gases round the sun by light around the hot center.

141. What is meant by freeze drying?

The process of removing water from a substance by lowering the temperature and atmospheric pressure.

142. What is frictional electricity?

The electricity which is produced by rubbing glass with silk or fur cloth.

143. What is a fumarole?

This is a small hole in a volcano from which fumes come out.

144. What is a fulcrum ?

This is the point on which a lever operates.

145. What is a fumigant?

A substance which is burned to make smoke, so that it kills insects.

146. What is an Electric Fuse?

This is a small piece of special lead wire, which melts when excess of current passes throught , thus breaking the circuit. It is also a safety measure for electrical circuits. 

147. What is galvanized iron?

This is iron coated with zinc. 

148. What is a galvanometer?

It is an instrument for measuring small currents of electricity. 

149. What is gamma iron?

This is non magnetic iron, which forms austentite, a form of steel. Gamma iron is iron mixed with carbon or alloys dissolved in it. 

150. Whai is a gasket?

A soft flat piece put between two metals surfaces to make a gas tight joint. A rubber gasket is used in pressure cooker to ensure pressure is built up and food is cooked well. 

151. What is a gas scrubber?

This is an instrument to remove impurities from coal gas.