Answer:
Option (C) is correct.
Explanation:
Assuming that the hiker starts walking from the origin O as shown in the figure.
First, he walks 200 m west to point A (say), then he walks 100 m north to the final point B (say) as shown in the figure.
The final point B is in the north-west direction, therefore, the resulting point is in the north-west direction.
Hence, option (C) is correct.
The period of a pendulum is given by

since Karachi is near sea level, g is larger than it is on Mt. Everest. That means the pendulum will have a larger period on Mt. Everest than it would in Karachi.
Answer:
The first law of thermodynamics doesn't actually specify that matter can neither be created nor destroyed, but instead that the total amount of energy in a closed system cannot be created nor destroyed (though it can be changed from one form to another).
Explanation:
Answer:
Water
Explanation:
windmills were used to bring water to farms in ancient times.
Answer:
As we are converting 220V AC into a 5V DC, first we need a step-down transformer to reduce such high voltage. Here we have used 9-0-9 1A step-down transformer, which convert 220V AC to 9V AC. In transformer there are primary and secondary coils which step up or step down the voltage according to the no of turn in the coils.
Selection of proper transformer is very important. Current rating depends upon the Current requirement of Load circuit (circuit which will use the generate DC). The voltage rating should be more than the required voltage. Means if we need 5V DC, transformer should at least have a rating of 7V, because voltage regulator IC 7805 at least need 2V more i.e. 7V to provide a 5V voltage.