Q1. What is measured in cusecs? (a) Purity of water (b) Depth of water (c) Flow of water (d) Quantity of water Q2. The apparatus used for detecting lie is known as- (a) Polygraph (b) Pyrometer (c) Gyroscope (d) Kymograph Q3. An ice cube is floating in a glass of water. What happens to the water level when the ice melts? It- (a) Rises (b) Falls (c) Remains the same (d) First rises and then falls Q4. Which one of the colours has the longest wavelength? (a) Green (b) Yellow (c) Blue (d) Red Q5. The least distance of distinct vision is (cms.) (a) 25 (b) 5 (c) 75 (d) 100 Q6. In human eye, image of object forms at (a) Cornea (b) Iris (c) Pupil (d) Retina Q7. The body temperature of a healthy man is- (a) 37° Celsius (b) 37° Fahrenheit (c) 98.4° Celsius (d) 98.4% Kelvin Q8. What is the use of thermostat? (a) To measure the temperature (b) To increase the temperature (c) To maintain the temperature (d) To convert heat into electricity Q9. Long radio waves are reflected by which of the following layer of earth’s surface- (a) Troposphere (b) Ionosphere (c) Tropopause (d) Stratosphere Q10. In which of the following option sound may not be across/travel? (a) Water (b) vacuum (c) Iron (d) Air Q11. The device used for converting alternating current to direct current is called (a) Inverter (b) Rectifier (c) Transformer (d) Transmitter Q12. Which of the following is a semiconductor? (a) Plastic (b) Aluminium (c) Wood (d) Germanium Q13. Which Uranium isotope is used in nuclear power plants to produce electricity? (a) U-233 (b) U-234 (c) U-235 (d) U-239 Q14. Which one of the following is India’s first nuclear plant? (a) Narora (b) Kalpakkam (c) Tarapur (d) Kota Q15. Mouse is- (a) Memory (b) C.P.U. (c) Input Device (d) Output Device
Sol. Cusec (Cubic feet per second) is a unit of measuring the flow of water.
Sol. A Polygraph popularly referred to as a lie detector, measures and records several physiological indices such as blood pressure, pulse, respiration, and skin conductivity while the subject is asked and answers a series of questions.
Sol. According to Archimedes principle, floating object displaces an amount of water equal to its own weight. Thus, the water level remains the same when the ice cube melts.
Sol. Wavelength of red colour is largest and violet colour has the shortest wavelength.
Sol. The minimum distance of an object from eye to have its clear image is called “Least Distance of Distinct vision”. It is about 25 cm for the normal eye and denoted by ‘D’.
Sol. In a normal eye, the image formed are transmitted from the retina to the brain along the optic nerve, where data processing takes place .
Sol. The normal core body temperature of a healthy, resting adult human being is stated to be at 98.6 degrees Fahrenheit or 37.0 degrees Celsius.
Sol. Thermostat is a device that automatically regulates temperature. It helps to save energy/power.
Sol. The ionosphere is a region of earth’s upper atmosphere from about 65 km. to 1000 km altitude. It has practical importance because among other functions, it influences radio propagation to distant places on earth.
Sol. Sound waves need a medium to travel. Vacuum is a situation of emptiness. So due to the absence of any medium in this situation, the sound waves may not be travelled.
Sol. Rectifier is an electric device that converts alternating current (AC) to direct current (DC)
Inverter is an electronic circuit that changes Direct Current (DC) to Alternating Current (AC).
Sol. Germanium and silicon are semiconductor materials.
Sol. U-238 and U-235 (which has 143 neutrons) are the most common isotopes of uranium. Uranium-235 is the isotope of uranium that is used in nuclear reactors.
Sol. Tarapur Atomic power station was the first nuclear power plant in India operational in 1969.
Sol. A mouse is a hardware input device that was invented by Douglas Engelbart in 1963.