20069.Intensity of sound has
an object existence
a subject existence
no existence
both subjective and objective existence
20062.Rainbow is produced when sunlight fall on drops of rain. Which of the following physical phenomena are responsible for this?
- Diffusion
- Refraction
- Internal reflection
I, II and III
I and II
II and III
I and III
20063.Natural radioactivity was discovered by
Marie Curie
Ernest Rutherfor
Henri Becquerel
Enrico Fermi
20070.Rain is falling vertically downwards. To a man running east-wards, the rain will appear to be coming from
east
west
northeast
southeast
20068.Minimum number of unequal vectors which can give zero resultant are
two
three
four
more than four
20071.An aeroplane is flying horizontally with a velocity of 600 km/h and at a height of 1960 m. When it is vertically at a point A on the ground a bomb is released from it. The bomb strikes the ground at point B. The distance AB is
1200 m
0.33 km
3.33 km
33 km
20067.It is easier to roll a barrel full of coal tar than to pull it because
the full weight of the barrel comes into play when it is pulled
the rolling friction is much less than the sliding friction
more surface area of the barrel is in contact with the road when it is pulled
coal tar is a liquid and it flows in the barrel when it is rolled
20066.Mica is used in electrical appliances such as electric iron because mica is
a good conductor of heat but a bad conductor of electricity
a bad conductor of heat but a good conductor of electricity
a good conductor of heat as well as electricity
a bad conductor of heat as well as electricity
20064.Planets are
luminous heavenly bodies revolving around a star
non-luminous heavenly bodies
luminous heavenly bodies that twinkle
luminous heavenly bodies that do not twinkle