41. When water is boiling, it
- A. gets hotter
- B. increase is mass
- C. decreases in mass
- D. changes to steam
42. A mixture of blue and red pigment when illuminated by white light will appear
- A. green
- B. orange
- C. purple
- D. magenta
43. A siren having a ring of 200 hole makes 132 rev/min. A jet of air is directed on the set of holes. Calculate the frequency and wavelength in air of the note produced (take v = 350m/s)
- A. 0.875m
- B. 0.625m
- C. 0.335m
- D. 0.125m
44. A man on a bench will exert the greatest pressure on the bench when he
- A. lies flat on his back
- B. lies flat on his belly
- C. stands on both feet
- D. stands on the toes of one foot
45. Gases conduct electricity under
- A. high pressure & high voltage
- B. low pressure & low voltage
- C. normal pressure & low voltage
- D. low pressure & high voltage
46. Neutrons were discovered by
- A. Faraday
- B. Dalton
- C. James Chadwick
- D. Rutherford
47. The mass of a nucleus is the
- A. total number of its proton & neutrons
- B. number of its protons
- C. mass of its electrons
- D. total number of its protons & electrons
48. Three resistors with resistance 200Ω, 500Ω and 1kΩ are connected in series. A 6v battery is connected to either end of the combination. Calculate the potential difference between the ends of 200Ω resistance.
- A. 0.71V
- B. 0.7V
- C. 0.82V
- D. 0.8V
49. An a.c of 1A at a frequency of 800 cycles per second flows through a coil, the inductance of which is 2.5mH and the resistance of which is 5Ω. What is the power absorbed in the Coil?
- A. 5W
- B. 6W
- C. 7W
- D. 8W
50. In semi-conductor, the carriers of current at room temperature are
- A. electrons only
- B. electrons and holes
- C. holes only
- D. electron and ions
