Physics-
General
Easy
Question
Assertion : When a beetle moves along the sand with in a few tens of centimeters of a sand scorpion the scorpion immediately turn towards the beetle and dashes to it
Reason : When a beetle disturbs the sand, it sends pulses along the sands surface one set of pulses is longitudinal while other set is transverse.
- If both assertion and reason are true and the reason is the correct explanation of the assertion.
- If both assertion and reason are true but reason is not the correct explanation of the assertion.
- If assertion is true but reason is false.
- If the assertion and reason both are false.
The correct answer is: If both assertion and reason are true and the reason is the correct explanation of the assertion.
A beetle motion sends fast longitudinal pulses and slower transverse waves along the sends surface. The sand scorpion first intercept the longitudinal pulses and learns the direction of the beetle; it is in the direction of which ever leg is disturbed earliest by the pulses. The scorpion then senses the time interval (Dt) between that first interception and the interception of slower transverse waves and uses it to determine the distance of the beetle. The distance is given by 
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Assertion : On a rainy day sound travel slower than on a dry day.
Reason : When moisture is present in air the density of air increases.
Assertion : On a rainy day sound travel slower than on a dry day.
Reason : When moisture is present in air the density of air increases.
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If the speed of the wave shown in the figure is 330m/s in the given medium, then the equation of the wave propagating in the positive x-direction will be (all quantities are in M.K.S. units)
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The figure shows four progressive waves A, B, C, and D with their phases expressed with respect to the wave A. It can be concluded from the figure that
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The rope shown at an instant is carrying a wave travelling towards right, created by a source vibrating at a frequency n. Consider the following statements
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Vibrating tuning fork of frequency n is placed near the open end of a long cylindrical tube. The tube has a side opening and is fitted with a movable reflecting piston. As the piston is moved through 8.75 cm, the intensity of sound changes from a maximum to minimum. If the speed of sound is 350 m/s. Then n is
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Physics-General
