Assertion and Reasoning questions is an important section as far as the Aptitude section is concerned. You have to decide if both the statements are correct or not, and see whether the reasoning is a correct explanation of assertion statement or not. Interpretation plays a key role in solving questions related to this type.
Once you are done with this section, you can go to Statements and Conclusions Aptitude Questions.
Assertion (A) : Most of the Himalayan rivers are perennial.
Reason (R) : They are fed by melting snow.
Most Himalayan river are perennial because they are fed by the melting snow throughout the year.
Thus, R correctly explains A.
Assertion (A) : Bangladesh imports jute from India.
Reason (R) : Bangladesh has most of the jute mills.
When Bangladesh was created after partition of India, the areas of jute production went to Bangladesh while the jute mills were left in India. So, India imports raw jute from Bangladesh.
Thus, both A and R are false.
Assertion (A) : Alcohol rather than mercury is used in a thermometer to measure a temperature of -60°C.
Reason (R) : Alcohol has a lower freezing point than mercury.
Mercury freezes at - 39°C, while alcohol freezes at a point far below-100°C. So, alcohol is used to measure lower temperatures. Similarly, mercury boils at 357°C while alcohol boils at 78°C. so, mercury is used to measure high temperatures.
Assertion (A) : Areas near the Equator receive rainfall throughout the year.
Reason (R) : High temperatures and high humidity causes conventional rain in most afternoons near the Equator.
R is correct explanation to A.
Assertion (A) : Tides indicate the regular and periodic rise and fall in sea level.
Reason (R) : Tides are caused by the gravitational pull of the moon and the sun.
R explains A fully.
Assertion (A) : There is rainbow in the sky only after rains.
Reason (R) : Water drops suspended in the air break up sun's rays into seven colours.
Water droplets act like prisms. Sun's rays falling on water droplets suffer dispersion and produce a spectrum.
Assertion (A) : No food material normally enters the wind pipe during swallowing
Reason (R) : When the swallow, the back portion of our tongue covers the opening of the wind pipe.
R explains A fully.
Assertion (A) : Comets belong to the solar system.
Reason (R) : All comets come near the sun after regular intervals.
Comets are included in the solar system as they are thought to be the remnants of or the actual building blocks of the outer planets.
Assertion (A) : An iron ball floats on mercury but gets immersed in water.
Reason (R) : The specific gravity of iron is more than that of mercury.
Iron with specific gravity less than of mercury but more than that of water floats in the former but gets immersed in the second.
Thus, A is true but R is false.
Assertion (A) : The British sovereignty continued to exist in free India.
Reason (R) : The British sovereign appointed the last Governor-General of free India.
India drafted its own Constitution and formed its own government after gaining independence. So, A is false. But R is true.