12. of the following chemicals, the one which will burn on contact with a lighted match is\na. carbon…

12. of the following chemicals, the one which will burn on contact with a lighted match is\na. carbon tetrachloride\nb. acetone\nc. methylene chloride\nd. sodium bicarbonate\n13. of the following, the best method of disposing of spray cans that contain aerosol paints or solvents is\na. puncturing the cans and then throwing them into an incinerator\nb. puncturing the cans and then having them picked up by the sanitation men\nc. throwing them into an incinerator\nd. having them picked up by the sanitation men\n14. an ohmmeter of known polarity is connected from the base to the emitter on a transistor in such manner that the positive lead is on the base. the ohmmeter registers continuity with such conditions and then registers an \open\ circuit when the leads are reversed. based on this information, it should be concluded that the transistor is\na. good\nb. defective\nc. an npn\nd. a pnp\n15. an ohmmeter registers \open\ when connected from the emitter to the collector of a transistor (base left disconnected) and also registers \open\ when the leads are reversed. this information suggests that the transistor is\na. possibly good\nb. definitely defective\nc. an npn\nd. a pnp

12. of the following chemicals, the one which will burn on contact with a lighted match is\na. carbon tetrachloride\nb. acetone\nc. methylene chloride\nd. sodium bicarbonate\n13. of the following, the best method of disposing of spray cans that contain aerosol paints or solvents is\na. puncturing the cans and then throwing them into an incinerator\nb. puncturing the cans and then having them picked up by the sanitation men\nc. throwing them into an incinerator\nd. having them picked up by the sanitation men\n14. an ohmmeter of known polarity is connected from the base to the emitter on a transistor in such manner that the positive lead is on the base. the ohmmeter registers continuity with such conditions and then registers an \open\ circuit when the leads are reversed. based on this information, it should be concluded that the transistor is\na. good\nb. defective\nc. an npn\nd. a pnp\n15. an ohmmeter registers \open\ when connected from the emitter to the collector of a transistor (base left disconnected) and also registers \open\ when the leads are reversed. this information suggests that the transistor is\na. possibly good\nb. definitely defective\nc. an npn\nd. a pnp

Answer

Brief Explanations:

Acetone is a flammable liquid. Carbon - tetrachloride, methylene chloride are not flammable and sodium bicarbonate is a non - flammable solid.

Answer:

B. acetone

Brief Explanations:

Puncturing spray cans with aerosols can be dangerous as it may cause an explosion. The best way is to have them picked up by sanitation men who can handle them properly.

Answer:

D. having them picked up by the sanitation men

Brief Explanations:

For an NPN transistor, when the positive lead of the ohmmeter is on the base and the negative on the emitter, there is continuity. When reversed, it shows an open - circuit.

Answer:

C. an NPN

Brief Explanations:

If an ohmmeter registers "open" when connected from emitter to collector (base disconnected) and also when leads are reversed, the transistor is likely defective.

Answer:

B. definitely defective