Find out the energy changes in the following statements? An electric bulb is lit Burning of firewood Photo synthesis While working an electric motor A cracker is bursting

Read the following statements and write whether true or false: During photo electric effect photon share its energy with a group of electrons.

Energy of a body is defined as its capacity of doing work. State whether the following statement is TRUE or FALSE. "The change in kinetic energy of a particle is equal to the work done on it by the net force"

Pick out the two scalar quantities in the following list: force,angular momentum,work,current,linear momentum,electric field,average velocity,magnetic moment,relative velocity.

Which of the following statements are correct? Fuel cells are galvanic cells in which the chemical energy of fuel is directly converted into electrical energy. Type of fuel cell is a hydrogen - oxygen fuel cell. It consists of two electrodes made up of two porous graphite impregnated with a catalyst (platinum, silver, or metal oxide). The electrodes are placed in aqueous solution of NaOH. Oxygen nad hydrogen are continuously fed into the cell. Hydrogen gets oxidized to H^(oplus) which is neutralized by overset(Θ)(OH) , ie., anodic reaction. H_(2) hArr 2H^(oplus) + 2e^(-) 2H^(oplus) + 2 overset(Θ)(OH) hArr 2H_(2)O H_(2) + 2 overset(Θ)(OH) hArr 2H_(2)O + 2e^(-) At cathode, O_(2) gets reduced to overset(Θ)(OH) i.e., O_(2) + 2H_(2)O + 4e^(-) hArr overset(Θ)(4)OH Hence, the net reaction is 2H_(2) + O_(2) hArr 2H_(2)O The overall reaction has Delta H= -285.6kJ mol^(-1) and Delta G= -237.4kJ mol^(-1) " at " 25^(@)C A fuel cell is I. A voltaic cell in which continuous supply of fuels are sent at anode to perform oxidation II. A voltaic cell in which fuels such as CH_(4), H_(2) and CO are used up at anode. III. One which involves the reaction of H_(2)- O_(2) fuel cell such as: Anode 2H_(2) + 4 overset(Θ)(OH) rarr 4H_(2)O(I) + 4e^(-) cathode : O+ 2H_(2)O(I) + 4e^(-) rarr 4 overset(Θ)(OH) IV. The efficiency of H_(2)-O_(2) fuel cell is 70 to 75%

When a charged particle moves in an electric field, work is done on the particle:- Pick out a vector quantity for the following. (a)electric potential (b)electric potential gradient (c)electric potential energy. (d)electric flux