# Physics Class 12th Chapter-3 Current Electricity Most VVI Subjective Questions

### Q.1. Write down two characteristics of fuse wire.

Ans- (1) High conductivity.

(2) Low melting point.

Q.2. Why is internal resistance of a secondary cell low ?

Ans- The secondary cell with provide higher value of maximum current so the value of internal resistance of secondary cell is lower than primary cell.

Q.3. Explain that Kirchoff’s second law is law of conservation of energy.

Ans- Kirchoff’s second law is based on the law of conservation of energy. As the electrostatics force is a conservative force so the work done by it along any closed path must be zero and power generated by battery distributes in all components.

Q.4. State and explain Thomson or Seeback effect.

Ans- Thomson effect – The observed action of emission of heat along the length of a conductor on passing current through it, when it’s two ends are kept at different temperature is known as Thomson effect.

Seeback Effect- The phenomenon of generation of an electric current in the in a thermocouple by keeping is Junction at different temperature is called seeback effect or thermoelectric effect. The potential difference between the junctions is called thermoelectric EMF which is of the order of a few micro-volt per degree temperature.

Q.5. Write any two factors o. which thermo EMF produced in Thermocouple depends.

Ans- The two factor on which thermo EMF produced in thermocouple depends are following.