Physics Past Questions and Answers

A rectangular solid black has length 10cm, breadth 5cm and height 2cm. If it lies on a horizontal surface, and has density 100kg/m\(^3\), calculate the pressure it exerts on the surface.

A 200 N/m\(^2\)
B 300 N/m\(^2\)
C 100 N/m\(^2\)
D 400 N/m\(^2\)

Question 2177:

The diagram shows four positions of the bob of a simple pendulum. At which of these positions does the bob have maximum kinetic energy and minimum potential energy

Question 2178:

An object is acted upon by a system of parallel three causing the object to be in state equilibrium. Which of the following statement is not correct

A The resultant of the parallel forces is zero
B The algebraic sum of all the moments of the forces is zero
C All the parallel forces must be equal in magnitude and direction
D The sum of forces in one direction must be equal to the sum of forces in the opposite direction

Question 2179:

Which of the following statements is/are correct for a freely falling body?<br/>I. the total is entirely kinetic<br/>II. the ratio of potential energy to kinetic energy is constant<br/>III. the sum of potential and kinetic energy is constant

A I only
B II only
C III only
D I & III only

Question 2180:

Efficiency of conduction in liquids and gases compared to solids is

A Less efficient than solid
B More efficient than solids
C Equally efficient to solids
D Efficiently may vary