A scientist took a metal rod and a wooden rod and wrapped each of them in a piece of paper. These were then heated as shown. It was found that the paper around the metal rod does not burn whereas the one around the wooden rod catches fire. It is because
(A) Iron being a good conductor, conducts away heat given to paper
(B) Wood being an insulator, takes away all the heat
(C) Candle in case of iron rod, is near to the paper
(D) Paper, in first case, it thicker.
In the experiment below, when the flask
was placed in hot water, the level of the drop of
ink dropped and then rose because the __________ expanded first, followed by the expansion
(A) Flask; air in the flask
(B) Air in the flask; flask
(C) Water; air in the flask
(D) Air in the flask; water.
Which one of the following statements is not true?
(A) Friction helps us to twist an object
(B) Friction is a force that opposes motion
(C) Objects have weight because of the frictional force between them and the Earth
(D) More friction is produced between rough surfaces than between smooth surfaces.
4 The speed of a train increases at a constant rate a from zero to v, and then remains constant for an interval, and finally decreases to zero at a constant rate b. If L be the total distance travelled, then the total time taken is
A particle is moving in a straight line with initial velocity u and uniform acceleration f. If the sum of the distances travelled in tth and (t + 1)th seconds is 100 cm, then its velocity after t seconds in cm/s is
The train route from Goa to Kerala has a total of 2000 bridges and 92 tunnels. Why do you think there are so many bridges and tunnels ?
When I selected option C then it said option D is correct and now it is saying D is incorrect
Which square must be shaded so that the figure has a line of symmetry ?
even after shading 1 the figure will not be symetric.please reveiw this question.
A particle of mass 0.3 kg is subjected to a force F = kx with k = 15 N/m and x being its distance from the origin. What will be its initial acceleration if it is released from a point 20 cm away from the origin ?
(A) 5 m/s2
(B) 10 m/s2
(C) 3 m/s2
(D) 15 m/s2