General Science MCQ — 109 Practice Questions with Answers

Explanation

For red-cell transfusion, the universal donor blood type is O negative, not AB positive. Therefore the pair "AB+ blood group - Universal Donor" is the mismatched pair. Hence D is correct.

Explanation

The natural greenhouse effect keeps Earth's surface warm enough for life, so Statement I is true. Protection from harmful ultraviolet radiation is mainly due to the stratospheric ozone layer, while tropospheric or ground-level ozone is treated as a pollutant. Therefore Statement II is false, and option C is correct.

Explanation

Mucormycosis, often called black fungus, is caused by molds of the order Mucorales. Mucor is one of the causative genera, while Lycopodium is a plant, Penicillium is not the usual cause of mucormycosis, and Leptospira is a bacterium. Therefore option A is correct.

Explanation

Bora is defined by Britannica as a very strong cold wind of the Adriatic region. Sirocco, Zonda and Khamsin are treated as warm or hot local winds in standard geography references. Thus the wind that is not hot is Bora, so option D is correct.

Explanation

An AM wave can be produced by applying the message signal and carrier wave to a non-linear device and then selecting the required band with a band-pass filter, so Statement A is true. After filtering, the AM wave contains the carrier and the two sideband frequencies, not ωm, 2ωm and ωc each with the same amplitude. Therefore only Statement A is true, so B is correct.