science & tech MCQ section 7 MCQ Questions & Answers Detailed Explanation

Answer: (d)

Microwaves are electromagnetic waves with wavelengths ranging from as long as one meter to as short as one millimetre, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz. A microwave oven passes (nonionizing microwave radiation (at a frequency near 2.45 GHz) through food, causing dielectric heating by absorption of energy in the water, fats and sugar contained in the food.

Bluetooth and Wi-Fi have many applications: setting up networks, printing, or transferring files. They also work in the given frequency range. All cordless sold in the US use the 1.9 GHz or 2.4-GHz bands.

Answer: (a)

The chromosphere (literally, “sphere of colour”) is the second of the three main layers in the Sun’s atmosphere and is roughly 2,000 kilometers deep. It sits just above the photosphere and just below the solar transition region. Helium, the lighter of the noble gases, was the first to be discovered. In fact, this element was first identified in the Sun’s chromosphere rather than in the Earth.

Answer: (c)

AMCA will be fitted with K9 or K10 engines. The engines will be developed in collaboration with a foreign manufacturer.

Answer: (b)

Living cells or tissues or organs are cultured in aseptic conditions in nutrient medium to produce plantlet which is disease resistant. This is known as tissue culture or micropropagation.

Answer: (b)

The tablets will be used to treat HIV-1 infection.

Answer: (a)

Kiran MK 11: Aerobatic aircraft

MI 35 : Attack helicopter

Mirage 2000 is a jet fighter aircraft