What are refrigerants? How do they chill the contents
inside a fridge?                                                268
Where does the water for frost formation in the
fridge come from?                                               269
What is the difference between an aircooler and
an air conditioner?                                             270
What is the black box (in planes) made of?
Normally what does it do?                                       272
When biscuits are kept in cool air, they lose their crispness.
Then how do they remain crisp, when they kept in a fridge?      272
How does one decipher bar codes?                                273
What is the composition of betelnut?                            274
Why does a layer form on top of hot beverages such
as milk and tea?                                                275
What is meant by empty calories got by drinking alcoholic
beverages?                                                      275
How do certain beverages give a feeling of freshness?           276
What is the difference between corn, sweetcorn and
popping corn? What makes sweetcorn sweet and
popping corn pop?                                               276
What is a speech synthesiser? How does it work?                 278
How does a lie detector work?                                   279
How does churning help in separating butter from curd?          280
Why does the inner side of a candle flame appear dark?          280
Why does a small piece of wood catch fire quickly rather than
a large log of wood?                                            281
Why do flames go upwards?                                       282
Why do flags flutter?                                           283
What makes the poori swell?                                     283
Why can’t we fry food with water instead of oil?                284
What happens to rice when it is boiled and wheat when baked?
Why is cooked food more digestible?                             284
How do crispy rice breakfast cereals make snap, crackle and
pop sounds when you pour milk on them?                          285
Why do we see stars when we receive a blow on the head?         286
No matter what colour of drink one consumes, when the
liquid finally leaves the body the colour has gone.
What happens to it?                                             287
Why is it that we are able to drink very hot liquid but the
same burns our skin if poured on the body?                      288
How does a pencil eraser work?                                  289
As a result of a broken leg, I now have a stainless steel rod
that runs down the centre of my femur. It is about a
foot long and 1.5 centimetre in diameter. The fractured
bone and rod are held together by a few screws each
about 8 centimetres long. The steel plate has never raised
airport security alarms although a small bunch of keys
that I carry has. Why?                                          290
Why do we tap our feet in time to music?                        291
How does a stick help people walk on ropes?                     291
How does mehndhi impart colour?                                 291
How are mummies made?                                           292
Why do we experience a blinding feeling when we enter a
dark room after standing in sunlight?                           293
Why is it difficult to shut wooden doors in winter?             294
In some cities extensive fogging with chemicals such as
malathion is being done routinely to control mosquitoes.
This chemical gets deposited on the fruits and vegetables
being grown in our gardens. Is it safe to eat those fruits?
How long does it take for the chemicals to get decomposed?      294
What constitutes bullet-proof glass?                            295
Why do thin glass tumblers break when filled with
very hot water?                                                 296
How does noise shatter glass?                                   296
How does a shaving brush help generate more lather from
soap or shaving cream?                                          297
What makes honey resistant to spoilage, even at room
temperature?                                                    298
How to verify purity of honey?                                  298
How does salt decrease the melting point of ice?                298
How is it that when a small piece of paper finds it difficult
to fly continuously in the air, kite made out of it is able
to fly easily?                                                  300
How do we dry clean our clothes?                                301
Why do we heat an iron box before pressing our clothes?         303
Why are some people left-handed? Is this type of preference
restricted to human alone?                                      304
Why are aeroplanes not affected by lightnings?                  306
Why is red meat red and white meat white? What is the
difference between the various animals that makes their
flesh differently coloured?                                     306
What are the constituents of mosquito mats? Are they not
harmful to human?                                               307
Why are engines fitted at the rear end in some vehicles?        308
How is a four-stroke engine of a two-wheeler more
eco-friendly than a two-stroke engine?                          309
What will happen if unleaded petrol is used in two-wheelers?    310
Why do we mix oil with petrol for two-wheelers?                 312
Can LPG be used to run petrol vehicles without any harm
to the engine?                                                  313
Why do two-wheelers not use diesel?                             314
Why are the rear wheels of tractors much larger than
the front wheels?                                               315
Why is not cutting nails and hairs, painful?                    316
Does eating gelatine really make your nails stronger?           317
What is bond paper? How is it different from other types
of paper?                                                       318
How does a blotting paper absorb ink?                           318
How do blotting paper and tissue paper differ from
ordinary paper?                                                 319
What is food poisoning?                                         320
Why are most eggs egg-shaped?                                   322
What is a `vegetarian egg'? How is it different from an
ordinary egg?                                                   323
How does a train stop when we pull the chain?                   324
How does boiled rice act as gum?                                324
What does the term `vacuum evaporated' printed on
iodised salt packets mean?                                      325
Why is TFM mentioned on soap wrappers?                          326
How is sound caused by cracking of knuckles?                    326
How is sound produced when the thumb and the middle
finger are clicked?                                             327
Why are satellites always launched from the east coast?         327
How does a cell phone work?                                     328
Why is it that one is able to hear the ring tone and not any
other noise when one dials a phone?                             330
How does a cordless phone work?                                 331
Why should we sit at a distance while watching the television?  332
When watching TV and the face of the person being
interviewed is obscured by large pixels of moving colour -
to conceal their identity - I can make out the elements
of their face more clearly if I squint. Why is this?            333
When I switch on my TV, audio is heard immediately but
video comes only after some time. Why?                          334
How does the service fault machine at tennis
tournaments work?                                               335
Why do clothes look dark when immersed in water?                335
Can vehicle tyres be filled with water instead of air?          336
Why are tubeless tyres not popular in India?                    337
What is meant by ply rating of tyres?                           337
What is the difference between radial and ordinary tyres?       338
Why is that, whatever they contain, dustbins always
smell the same?                                                 340
While leap years (divisible by four) get an extra day,
why are century years, unless divisible by 400, left out?       340
Why is a circle divided into 360 degrees?                       342
What is non-linear editing? How is it different from
linear editing?                                                 343
What is tear gas? How does it work?                             344
Index                                                           345