General Science and Technology Quiz

There are 4 main blood groups in the ABO system: A, B, AB, and O. Each can be Rh-positive or Rh-negative, creating 8 total types, but the fundamental groups are 4. This is the standard classification used worldwide for blood typing and transfusion compatibility.

A tooth has three main structural parts: the root (embedded in the jawbone), the pulp cavity (containing nerves and blood vessels), and dentine (the hard tissue between enamel and pulp). None of the other options have this specific combination of anatomical structures.

The skin is the largest organ in the human body, covering approximately 2 square meters in adults. It serves multiple functions including protection, temperature regulation, sensation, and vitamin D synthesis. The liver is the largest INTERNAL organ, but skin is larger overall.

The scapula, commonly known as the shoulder blade, is located on the upper back of the torso. It connects the humerus (upper arm bone) with the collarbone and forms part of the shoulder joint. The other options are locations where the scapula is not found.

Vitamin D is essential for calcium absorption and bone mineralization, making bones strong and healthy. It helps maintain adequate levels of calcium and phosphate in the blood, which are crucial for bone formation. Severe deficiency leads to rickets in children and osteomalacia in adults.

At Earth's exact center, gravity becomes zero because you're equally surrounded by mass in all directions. The gravitational pull from all sides cancels out completely. Gravity increases slightly as you go down from surface to the mantle, then decreases toward zero at the center.

Stars appear to twinkle (scintillation) because Earth's atmosphere has varying temperature and density layers that refract starlight differently as it passes through. This causes the light to bend and flicker. The option calls this 'pollution' but means atmospheric disturbance - the explanation is correct even if the wording is imprecise.

In a perfectly insulated closed room, a fan increases temperature. The fan's motor converts electrical energy to heat, and the air friction from the fan blades also generates thermal energy. While fans cool people by evaporation, they add net heat to a closed system.

The Sun produces energy through nuclear fusion, where hydrogen nuclei combine to form helium. This process converts mass to energy according to E=mc², releasing enormous heat and light. Fission is incorrect (that's splitting atoms), and the helium-to-hydrogen direction is backwards.

Negative acceleration means the acceleration vector points in the negative direction. Whether the object slows down or speeds up depends on the direction of its velocity - if velocity and acceleration have opposite signs, it slows down; if they have the same sign, it speeds up.

The total normal force you exert on the floor equals your weight (mg) in both cases, whether you're standing or lying down. This is a consequence of Newton's laws - the floor must push up with a force equal to your weight to support you. The difference is in pressure, not total force.

ISRO (Indian Space Research Organisation) has its headquarters in Bangalore (now Bengaluru). Delhi is the capital but not ISRO HQ, Thiruvananthapuram has Vikram Sarabhai Space Centre, and Sriharikotta is the launch pad.

Chandrayaan-1 was launched on October 22, 2008 using PSLV C11 rocket. PSLV C7 and C13 launched other satellites, and GSLV Mk II (not GSLV 11) is a different rocket class.

Rakesh Sharma became the first Indian to travel to space on April 2, 1984, as part of the Soviet Intercosmos program. He flew aboard Soyuz T-11 to the Salyut 7 space station.

Kalpana-1 was India's first dedicated meteorological satellite, launched in 2002. It provided weather monitoring and cyclone warning services. Options A and D are incorrect - Kalpana-1 was neither a spaceship nor a lunar mission. Option B (geosynchronous) is also incorrect; while it was in geostationary orbit, its primary classification was meteorological, not just a communication satellite.

G. Madhavan Nair served as Chairman of ISRO from 2003 to 2009, overseeing missions like Chandrayaan-1. K. Kasturirangan (option A, misspelled) was his predecessor. A. P. J. Abdul Kalam was a former ISRO chairman but not current in the exam's timeframe. Rakesh Sharma is a cosmonaut, not ISRO chairman.

G. Madhavan Nair served as Chairman of ISRO from 2003 to 2009, overseeing missions like Chandrayaan-1. K. Kasturirangan (option A, misspelled) was his predecessor. A. P. J. Abdul Kalam was a former ISRO chairman but not current in the exam's timeframe. Rakesh Sharma is a cosmonaut, not ISRO chairman.

Aryabhatta, launched in 1975, was India's first satellite. Rohini was a later series, Bhaskara 1 and 2 were experimental remote sensing satellites launched after Aryabhatta.

Hydrostatic bearings use an external pressure source to create a fluid film, making them ideal for very heavy loads at slow speeds. Hydrodynamic bearings rely on relative motion and are better for higher speeds. Ball and roller bearings have load limitations compared to fluid film bearings.

A key in mechanical assembly fails by both crushing (compressive stress from the shaft) and shearing (transverse shear stress). The combined stress state makes it susceptible to both failure modes simultaneously, which is why key design considers both crushing and shear stresses.