Question

State the energy changes taking place in the following cases: 

(a) Glowing of a torch bulb 

(b) A toy car is wound and then allowed to move on the floor 

(c) A truck climbing up a hill 

(d) Water in a dam rotates a turbine coupled to a generator 

(e) An air gun is loaded and then fired 

(f) A piece of magnesium burns in air 

(g) Water freezes in the freezing chamber of a fridge 

(h) A stone dropped from a cliff 

(i) Food eaten by humans 

(j) Exposure of photographic film in sunlight 

Answer 1

(a) Electric energy into heat light energy. 

(b) Potential energy into mechanical energy or kinetic energy. 

(c) Heat energy into mechanical (P.E.) energy 

(d) E. of water into electrical energy. 

(e) Potential energy of spring into K.E. of bullet (pallel) 

(f) Chemical energy into heat energy. 

(g) Electrical energy into mechanical energy (to run compresor) 

(h) Chemical energy into heat energy. 

(i) Potential energy into kinetic energy. 

(j) Light energy of Sun into chemical energy.