Questions

The data bus is Bi-directional because the same bus is used for transfer of data between Micro Processor and momory of input / output devices in both the direction.

Hedging is a tool to minimize the risks. It is thus like an 'insurance' where one pays a premium but gets an assured amount in case of some uncertain event to the extent of the loss actually suffered on an equally opposite position for which the hedge was done. Thus, hedger is different from arbitrageur and speculators, as the intention here is not to maximize the profit but to minimize the loss.

E.g. In Capital Markets, suppose an investor has an equity portfolio of Rs. 2 lacs and the portfolio consists of all the major stocks of NIFTY. He thinks the market will improve in the long run but might go on a downside in the shortrun. NIFTY today stands at 4300. To minimize the risk of downfall, he enters into an option contract by buying NIFTY-PUT of strike 4300 at a premium of, say, Rs. 100. Thus, the actual amount paid is Rs. 5,000(lot size of NIFTY is 50). Also, the number of NIFTY-PUTs to be bought will vary on the beta of the portfolio so as to completely hedge the positon. 

Gamma rays has the shortest wavelength and radio waves has the longest wavelength.

We know that, 

Earth is known as Watery planet.

Neptune is known as Blue planet. 

The nervous system of the human brain consists of the central nervous system which has brain and the spinal cord and the peripheral nervous system which has perpheral, cranary, spinal nerves.