What is the sign convention for work?

What is the sign convention for heat ?

An ideal gas enclosed in a cylinder fitted with a frictionless and weightless piston, pushes it outside. What would be the sign convention for the work ?

An ideal gas enclosed in a cylinder fitted with a frictionless and weightless piston, pushes it outside. What would be the sign convention for the work ?

What would be the sign convention for work done on a system for a cylinder containing one mole of an ideal gas where P_(ext) = P_(int) ?

What would be the sign convention for work done on a system for a cylinder containing one mole of an ideal gas where P_(ext) = P_(int) ?

If the external pressure is more than internal pressure then what will be the sign convention for the work done on a cylinder fitted with a frictionless and weightless pistion containing one mole of an ideal gas?

Write the sign conventions for spherical mirrors.

What is the sign of DeltaS for a spontaneous reaction ?

(a) Draw the ray diagram for the formation of image of an object by a convex mirror and use it (along with the sign convention) to derive the mirror formula. (b) Use the mirror formula to show that for an object, kept between the pole and focus of a concave mirror the image appears to be formed behind the mirror.

Which of the following is the non conventional source of energy