Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 v.

(a) Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known ? (b) How much heat will an instrument of 1 2 W produce in one minute if it is connected to a battery of 1 2 V ? (c) The current passing through a room heater has been halved. What will happen to the heat produced by it ? (d) What is meant by the heating effect of current ? Give two applications of the heating effect of current . (e) Name the material which is used for making the filaments of an electric bulb. Explain the following. (a) Why is the tungsten used almost exclusively for filament of electric lamps? (b) Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal? (c) Why is the series arrangement not used for domestic circuits? (d) How does the resistance of a wire vary with its area of cross section? (e) Why are copper and aluminium wires usually employed for electricity transmission?

NCERT Questions In Text Questions Question 1. What does an electric circuit mean ? (CBSE 2011, 2013, 2014) Answer: An electric circuit is a closed conducting path containing a source of potential difference or electric energy (i.e. a cell or battery) and a device or element utilizing the electric energy. More Resources • • • • • Question 2. Define the unit of current. (CBSE 2008) Answer: Unit of electric current is ampere. Electric current in a conductor is said to be 1 A if 1 coulomb charge flows through the cross-section of the conductor in 1 second. Question 3. Calculate the number of electrons consisting one coulomb of charge. (CBSE 2015) Answer: Question 4. Name a device that helps to maintain a potential difference across a conductor. (CBSE 2008) Answer: A cell or battery. Question 5. What is meant by saying that a potential difference between two points is 1 V ? [CBSE (Delhi) 2008 ; CBSE (All India) 2008, 2010 Term I] Or Define the term “Volt”. (CBSE 2009, 2013) Answer: Potential difference between two points is 1 V if 1 joule work is done in moving 1 coulomb charge from one point to another point. Question 6. How much energy is given to each coulomb of charge passing through a 6 V battery ? Answer: Energy = Charge x Potential difference =1 C X 6 V = 6 J. Question 7. On what factors does the resistance of a conductor depend ? (CBSE 2009, 2011, 2012, 2013, 2014) Answer: Resistance of a conductor depends on • length (l) of the conductors, • area of corss-section of th...