Wurtz reaction is carried out with sodium metal which is highly reactive, hence, we have to select a solvent which will not react with the sodium metal. Thus ether becomes the best choice. Similarly the alkyl halide should also dissolve in the solvent . The sodium halide formed should be insolulbe in the solvent which can be easily removed, and alkane formed should remain in solution,  

it requires an aprotic solvent as the medium of the reaction.Dry ether proves to be a very good non-polar, aprotic solvent for this purpose. Hence dry ether is used .

eg. CH₃I ----------> CH₃ - CH₃  (in presence of Sodium and Dry ether)

The induced emf,
{tex}\varepsilon = - \frac{{d\phi }}{{dt}}{/tex}
{tex}\varepsilon = \frac{d}{{dt}}(BA\cos \phi )(\because \cos \phi = 1){/tex}
{tex} = \frac{{20 \times 100 \times 4 \times {{10}^{ - 4}}}}{{0.2}}{/tex} = 4 volt.

AAPHER PHYSICAL FITNESS TEST : This test consists of the following six items :

1. Pull ups : In case of girls, the pull-ups are to be started from a flexed arm hang. This test item judges the arm and shoulder girdle strength.
2. Flexed Leg sit ups : This test is meant to judge the efficiency of abdominal and hip flexor muscles.
3. Shuttle Run : This test item is meant for judging the speed and change of direction.
4. Standing Long Jump : For judging the explosive power of leg muscles.
5. 50 yard Dash or Sprint : For judging speed.
6. 600 yard Run : For judging endurance.

Administration of Tests : these tests can be conducted in a gymnasium or out-doors. The only apparatus required in these tests is a horizontal bar having a diameter of approximately 1½ inches for pull-ups and flexed arm hang for girls. However, arrangement has to be made for the timing and recording of all scores with the help of timers and recorders.

Item No.1—Pull ups : This item has to be done from a hanging position on the bar by using the overhead grasp (with palms facing outwards). The arms and legs of a subject should be fully extended. Form hanging position, the subject should raise his body with his arms until his chin is placed over the bar. Then, he should lower his body to a full hanging position. In doing so, the knees should not be bent and the pull should not be jerky or snap pull. (The number of completed pull-ups is the score of the subject.)

Item No. 1 (Girls)—Flexed-arms hung: In this test item for girls, the subject is required to hang from the bar with flexed arms and overhead grasp. She should raise her body to a position where the chin is above the bar, the elbows are flexed and the chest is close to the bar. The stopwatch is started as soon as a subject assumes such a hanging position and is stopped when the subject‘s chin falls below the level of the bar. (The time recorded in seconds for which a subject holds the hang position is her score)

Item No. 2—Sit-ups : For this test meant for boys and girls, the subject should lie on his or her back with knees flexed and kept not more than 12 inches from the buttocks. The hands of the subject should be placed at the back of the neck, fingers clasped and elbows touching the mat. From this position, the subject should raise his or her head and elbows forward upwards till the elbows touch the knees. This constitutes one sit-up. (The number of correctly performed sit ups in 60 seconds from the start of the first sit-up is the score of a subject).

Item No. 3—Shuttle Run : For this test item, two parallel lines are drawn at a distance of 30 feet from each other and two blocks of wood are placed behind one of the lines. The subject has to stand behind the other line and on the signal ―Ready‖, ―Go‖ should run to pick up one block, run back to the starting line and place the block behind the line. He should again turn back to pick up the second block and bring it also behind the starting line. Two such trials are given. (The better time of the two trials to the nearest 10th of a second is the score of the subject).

Item No. 4—Standing Long Jump : In this test, a subject is required to stand behind a take-off line, with feet apart. He takes a jump forward by extending his bent knees and swinging the arms forward. The best jump recorded, out of the three trials given, is the score of the subject. (The jump should be recorded in feet and inches).

Item No. 5—50 Yard Dash : Two lines are drawn at a distance of 50 yards from each other. The subject is made to run from the start line to the finish line and his time taken is recorded in seconds (nearest to the tenth of a second.) This indicates his score.

Item No. 6—600 Yard Run : This run can be organized on a track, on a football field or an open area marked for this purpose. In this test item, a subject runs a distance of 600 yards. The subject takes a standing start from the start line. The subject may walk in between. However, the objective is to cover the distance in the shortest time. When he crosses the finish line, he is informed of his time. (The time taken to run the distance is recorded in minutes and seconds).

This statement can be justified by the following points:

a) With the passage of time, humans are able to innovate and develop the technology which can help to social and cultural development.

b) Humans are also able to create new possibilities with the resources obtained.

c) Examples include health resorts, orchads, pastures, ports on the coast and satellites in space.