aptitudetests4me.com
Aptitude Tests 4 Me


bulletPassage Reading

bulletVerbal Logic

bulletNon Verbal Logic

bulletNumerical Logic

bulletData Interpretation

bulletReasoning

bulletAnalytical Ability

bulletBasic Numeracy

bulletAbout Us

bulletContact

bulletPrivacy Policy

bulletGoogle Privacy & Terms

bulletSite Map Page

Passage Reading and English Comprehension

No very satisfactory account of the mechanism that caused the formation of the ocean basins has yet been given. The traditional view supposes that the upper mantle of the earth behaves as a liquid when it is subjected to small forces for long periods and that differences in temperature under oceans and continents are sufficient to produce convection in the mantle of the earth with rising convection currents under the mid-ocean ridges and sinking currents under the continents. Theoretically, this convection would carry the continental plates along as though they were on a conveyor belt and would provide the forces needed to produce the split that occurs along the ridge. This view may be correct: it has the advantage that the currents are driven by temperature differences that themselves depend on the position of the continents. Such a back-coupling, in which the position of the moving plate has an impact on the forces that move it, could produce complicated and varying motions.

On the other hand, the theory is implausible because convection does not normally occur along lines, and it certainly does not occur along lines broken by frequent offsets or changes in direction, as the ridge is. Also it is difficult to see how the theory applies to the plate between the Mid-Atlantic Ridge and the ridge in the Indian Ocean. This plate is growing on both sides, and since there is no intermediate trench, the two ridges must be moving apart. It would be odd if the rising convection currents kept exact pace with them. An alternative theory is that the sinking part of the plate, which is denser than the hotter surrounding mantle, pulls the rest of the plate after it. Again it is difficult to see how this applies to the ridge in the South Atlantic, where neither the African nor the American plate has a sinking part.

Another possibility is that the sinking plate cools the neighboring mantle and produces convection currents that move the plates. This last theory is attractive because it gives some hope of explaining the enclosed seas, such as the Sea of Japan. These seas have a typical oceanic floor, except that the floor is overlaid by several kilometers of sediment. Their floors have probably been sinking for long periods. It seems possible that a sinking current of cooled mantle material on the upper side of the plate might be the cause of such deep basins. The enclosed seas are an important feature of the earth’s surface, and seriously require explanation because, in addition to the enclosed seas that are developing at present behind island arcs, there are a number of older ones of possibly similar origin, such as the Gulf of Mexico, the Black Sea, and perhaps the North Sea.

228. According to the traditional view of the origin of the ocean basins, which of the following is sufficient to move the continental plates?

(a) Increases in sedimentation on ocean floors
(b) Spreading of ocean trenches
(c) Differences in temperature under oceans and continents
(d) Movement of mid-ocean ridges

229. It can be inferred from the passage that, of the following, the deepest sediments would be found in the

(a) Indian Ocean
(b) Black Sea
(c) Mid-Atlantic
(d) South Atlantic

230. The author refers to a “conveyor belt” in order to

(a) illustrate the effects of convection in the mantle
(b) show how temperature differences depend on the positions of the continents
(c) demonstrate the linear nature of the Mid-Atlantic Ridge
(d) describe the complicated motions made possible by back-coupling

231. The author regards the traditional view of the origin of the oceans with

(a) slight apprehension
(b) absolute indifference
(c) indignant anger
(d) guarded skepticism

232. According to the passage, which of the following are separated by a plate that is growing on both sides?

(a) The Pacific Ocean and the Sea of Japan
(b) The South Atlantic Ridge and the North Sea Ridge
(c) The Gulf of Mexico and the South Atlantic Ridge
(d) The Mid-Atlantic Ridge and the Indian Ocean Ridge

233. Which of the following, if it could be demonstrated, would most support the traditional view of ocean formation?

(a) Convection usually occurs along lines.
(b) The upper mantle behaves as a dense solid.
(c) Sedimentation occurs at a constant rate.
(d) Sinking plates cool the mantle.

234. According to the passage, the floor of the Black Sea can best be compared to a

(a) rapidly moving conveyor belt
(b) slowly settling foundation
(c) rapidly expanding balloon
(d) violently erupting volcano

235. Which of the following titles would best describe the content of the passage?

(a) A Description of the Oceans of the World
(b) Several Theories of Ocean Basin Formation
(c) The Traditional View of the Oceans
(d) Convection and Ocean Currents

TOTAL

Detailed Solution




Download Free EBooks for GMAT, GRE, ACT, SAT, LSAT, MCAT etc.

1. Passage Reading 2. Verbal Logic 3. Non Verbal Logic 4. Numerical Logic

5. Data Interpretation 6. Reasoning 7. Analytical Ability 8. Basic Numeracy

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180
181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220
221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240
241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260
261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280
281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300
301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320
321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340
341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360
361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380
381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400
401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419

Tell Your Freind

Your Name:
Your Friends Email Address:
Your Friends Name: