4261: Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?
(a) The Earth's magnetic field diverts them towards its poles
(b) Ozone layer around the Earth reflects them back to outer space
(c) Moisture in the upper layers of atmosphere prevents them from reaching the surface of the Earth
(d) None of the statements (a), (b) and (c) given above is correct
4262: What does Baudhayan theorem (Baudltayan Sulva sutra) relate to ?
(a) Lengths of sides of a right-angled triangle
(b) Calculation of the value of pi
(c) Logarithm calculations
(d) Normal distribution curve
4263: With reference to the treatment of cancerous tumours, a tool called cyberknife has been making the news. In this context, which one of the following statements is not correct ?
(a) It is a robotic image guided system
(b) It delivers an extremely precise dose of radiation
(c) It has the capability of achieving sub-millimetre accuracy
(d) It can map the spread of tumour in the body
4264: A universal donor has the blood group belonging to:
(a) A
(b) B
(c) O
(d) AB
4265: Hygrometer is used to measure:
(a) Density of a liquid
(b) Relative humidity of atmosphere
(c) Absorption power of plants
(d) Temperature of air