Q1 Connect these three statements which feature in the history of communication
" What God Hath wrought"
" Watson, come here I want you"
" Do you know abything kemp?"
A. First telegraph message. First telephone message. Graham bell to Watson.
Frist radio message from Marconi to Kemp.
Q2. What does the cassini division separate?
A.The rings of Saturn.
Q3.On Earth we use the directions North and South ,bearings etc for navigation. How do Astronauts and space expeditions navigate?
A. Like sailors of old. Using the stars etc.
Q4. Why does the throat dry up when we are scared or nervous?
A. In a state of tension etc. the body gives less importance to metabolic activities like digestion etc. Salivary glands are temporarily shut down so to speak.
Q5. Cyclone winds are those which have alow pressure region in the centre. They circle clockwise in the North and anticlockwise in the South. Which direction do they circle at the equator and why?
A. Direction is due to coriolis force. The Coriolis force isnot strong enough for them to form at the equator and if they do they are usually blown away either north or south.
Q6. Frozen carrots when put into the microwave to be warmed sometimes spark and can end up with charred ends. Why?
A. Due to the changing voltage field across a conductor which had an angular end(carrot) high heating takes plave over a localised surface are
A. This results in sparking and the heating causes charring.
Q7 In sunshine flies sometime sit on planks of wood all facing the same direction.Over time they tend to reorient themselves. Which dirn and why? (hint not the sun)
A. They align themselves with air currents for stability. This is less strenous than being buffetted by side winds or facing the opposite direction and getting their wings ruffled.
Q8 Heating water to boiling point in a mug using a microwave can cause it to explode violently when removed or boil furiously when a spoon or a teabag is put into it. Explain
A. In a mug there are no sites for nucleation(bubble formation) so when it is jostled or something slightly rough like a spoon etc is inserted the "superheated" water will boil.
Q9 Why do people with steel body parts not trigger off the metal detector in airports while their keybunches might.
A. They steel is made of austentite which is non magnetic. Metal detectors work by checking for response from a magnetic material.
Q10. After a night of heavy drinking people wake up finding their voices a lot deeper than before. Explain.
A. The relaxing effect on the brain also causes it to relax the vocal chords which decreases the pitch of the voice. This is what happens when some people sing as well. (that is why talking voices can be different from singing voices.)
Q11. The ability to hear with two ears on both sides of the head is called stereo vision. Would you be able to distinguish if a brief sound made perpendicular to the head was coming from the front or back?
A. No. Most sounds are bit lingering and we tend to incline our heads a bit in some direction and so be able to know if it is more left or right.
Q12 Two partially filled baloons one smaller than the other are connected bu a closed tube. What happens when the tube is opened. ?
A. The bigger balloon will expand. This is because stretched rubber is thinner tand easier to inflate.
Q13. Shaking a soft drink can and opening it spills some part of the contents. If a can is tapped a few times after being shaken, it willnot spurt so much upon opening. Why>
A. The tapping releases bubbles which have been trapped throughout the liquid so that they go to the top or combine with other bubbles so that less liquid is present as foam. So less is wasted.
Q14 Putting a lightbulb in a microwave causes it to glow. Why
A. The filament behave like a small antena with high resistance.Atoms vibrate at a much higher frequency since they are in an environment awash with radiation and dissipate it as light. (even better with fork i think)
Q15. Pubowners who use dishwashing fluid say that their customers get less foam.
A. Detergents in dishwashing fluid. Surface tension funda.
Q16 Elephants drink water by sucking it up through their nose and then putting it into their mouth. This is possible because unlike humans their breathing and digestion passages are disjoint. Babies can indulge in something similar before tthe two passages are joined in the mouth. What?
A. Suckling of babies is possible because they can breathe simultaneously while swallowing.
Q17 "People say that hair is dead. But my hair looks different at different times. Dry sometimes, silky when I was pregnant etc. How come?"
A. The sebacous glands in the scalp are responsible for secretion of oils etc which make your hair appear different at different times.
Q18 If camaflouge is so good in providing protection, how come excepting one or two species there are no green mammals?
A. Most mammals are colour blind so it doesnot matter. Most forms of camoflouge depend on having hides of different shades to blend in with the surrounding.
Q19 Some pubs sport juke boxes which have columns of liquids with bubbles flowing upwards. The bubbles get smaller as they move to the top. Given the info that there is a heater at the bottom of the column and that these devices donot require a pump explain.
A. The bubbles are of watervapour. As it reaches the top it condenses as it is away from the heatsource and so the bubbles get smaller. This is also why there is no need for a pump.
Q20 New SI unit representations--- Zepto 10^-21 Yocto 10^-24 Zetta 10 ^ 21 Yotta 10 ^ 24
Q21 Mr.Beer Belly went on a trip to Canada in winter and noticed that upon removing a bottle of beer from the refrigerator and opening it the beer sometimes tended to freeze. Why?
A. For freezing a seed is required which would be provided by the air when the bottle was opened so it freezes. Infact sometimes if he feels really greedy puors the beer into his mouth faster than the mouth can heat it to 0degreesC it will freeze there as well!!
Q22 Why do porous objects like concrete,paper etc seem to get darker when they are wet?
A. The porous objects usually reflect light from small sockets on their surface. Water fills these sockets and reduces the amount of reflection from the surface resulting is a darker appearance.