Physics Past Questions and Answers

A hydrometer is an instrument for measuring the

<img src='https://www.schoolngr.com/eattachments/3c6bdfed5c587baf1688c96dd54913e36215ac43' width='300'/><br/>Consider the three forces acting at O and in equilibrium as shown in the figure. Which of the following equations is/are CORRECT?<br/>I. P\(_1\) cos \(\theta_1\) = p\(_1\) cos \(\theta_2\)<br/>II. P\(_3\) = P\(_1\) cos \(\theta_4\) + P\(_2 cos_2\)<br/>III. P\(_1 \sin \theta_1 = P_2 \sin \theta_2\)

The refractive index of a liquid is 1.5. If the velocity of light in vacuum is 3.0 x 10\(^8ms^{-1}\), the velocity of light in the liquid is

A ship travelling towards a cliff receives the echo of its whistle after 3.5 seconds. A short while later, it receives the echo after 2.5 seconds. If the speed of sound in air under the prevalling condition is 250ms -1, how much closer is the ship to the cliff?

Which of the following statements about defects of vision is/are CORRECT? <br/>I. For a long sighted person, close objects appear blurred<br/>II. For a short sighted person, distant objects appear blurred <br/>III. Short sight is corrected by using a pair of converging lenses