(A) 313°C (X)
(B) 586°C (X)
(C) 819°C ()
(D) 1172°C (X)

Answers: The velocity of sound in air would become double than its velocity at 0°C at temperature 819°C.

(A) Remain unaffected (X)
(B) Fall away from the train (X)
(C) Fall towards the train ()
(D) Fall away from or towards the train depending upon the speed (X)

Answers: A train goes past a railway station at a high speed. A young boy standing on the edge of the platform is likely to  Fall towards the train.

(A) Red, green and blue ()
(B) Orange, back and violet (X)
(C) White. red and yellow (X)
(D) Yellow, green and blue (X)

Answers: Red, green and blue

(A) – 2O°C (X)
(B) – 10°C ()
(C) + 10°C (X)
(D) + 20°C (X)

Answers: A Fahrenheit thermometer indicates a temperature of ‘ 14°F. its corresponding reading on the Celsius scale will be  – 10°C.

(A) The value of ‘g’ is less in water (X)
(B) Density of air is less than that of water (X)
(C) Of the viscous force in water ()
(D) Of The surface tension of water (X)

Answers: .Lead ball falls through water more slowly than through air because   Of the viscous force in water.

(A) Concave (X)
(B) Plane (X)
(C) Convex ()
(D) Biconcave (X)

Answers: The rear view mirror of a motor vehicle is  Convex.