What are the effects of improper shutdown of computer?

The bad effects are that you would have you're OS get corrupted because the data in the memory are not dumped properly and that could cause errors once you restart your PC. So it's good to have a UPS available so you won't lose important data and files on your PC.

it's very dangerous.. your hard drive can be corrupted, so you can't open your computer after.. your motherboard could also be damage like damge in some chips or frequency stuff in the motherboard.. it can result to a very serious problem, like what happen on our neighbor their computer had a motherboard problem due to brown out... they paid 1 thousand pesos to the person who repaired their computer.. take good care of your computer.. have a nice day..

If you are working on something such as an Excel spreadsheet etcetera then your data will not be saved. The same scenario would apply if you were in the process of installing software or ceating a backup. Providing that there are no open programs, or at least none on which you are amending the contents, then there is unlikely to be any permanent issue. Some operating system files can become corrupt in such a case, but it is unlikely and can easily be rectified.

well if its not that common maybe none, but data loss is the biggest effect i have seen.

IF computer is not shutdown properly, There may be occurred following problems 1: Hard disk may be get bad sectors. 2: Working Data may be lost. 3: Operating System may be corrupted.