The bulb will light up with its normal brightness when supplied with 12V , where it'll dissipate 24 J of energy per second . Determine which circuit satisfies this requirement .

In fact, foxtrotalpha’s simple explanation of “attraction between electric charges” is sufficiently logical to deduce the correct path of the negatively charged particle. However, because you asked for the reason the particle behaves as shown in diagram C, it maybe necessary to to show you that the proton-packed nucleus is assumed to be way heavier than the negatively charged particle, by explaining from similarity in gravity-assist maneuvers involving a spacecraft.

Can anyone help in this? Vector for SPM

In a parallelogram OABC, it is given OA = a, OC = c, PB = 1/3 AB, BQ = 1/3 BC. OQ and AB are extended to meet at S while SB and OP are extended to meet at R.
a) Express   
    i) BS in terms of c
    ii) BR in terms of a
b) Show that RS is parallel to AC.
I am stucked with this question.
Thanks in advance.

that question has problem. from the diagram, two voltmeters are connected in series. every year spm paper has wrong questions. shame on the persons who set the questions. 

Perhaps you can get a better picture by reading my Post #1129 again.

Cathode Ray Tube acts as a rectifier to convert the A.C signal to a D.C . Capacitor blocks D.C , so the output would be that of C .

Critical_Fallacy please verify this as I've neglected Physics for quite a long time now , focusing on the languages and history .

Thanks for the heads up. 

II and III .

Lead ( II ) nitrate cannot be used because both Lead ( II ) chloride and Lead ( II ) sulphate are insoluble , white precipitates produced from the reaction with sulphuric acid and hydrochloric acid . Similarly , zinc carbonate in both acids will yield the same results .

Think of the individual ions that are present in the solution . Lead ( II ) nitrate and Barium nitrate are soluble salts , producing lead ( II ) ions and barium ions which react with chloride and sulphate present in the acids .

Do you have a thorough grasp on SPM Salts ? If you do , you'd know whether a mixture of a salt and an acid will yield a product or not based on the ions present . Not all soluble salts will react with acid , and the the acid itself has to be taken into account . Take sodium chloride for example , reacting with hydrochloric acid . No product will be formed .