Science
(a) State Joules law of heating and write its mathematical expression.
(b) Two resistors of resistances 2 Ω and 4 Ω are connected in
- series
- parallel
with a battery of given potential difference. Compute the ratio of total quantity of heat produced in the combination in the two cases if the total voltage and time are kept the same for both.
Related Questions
(a) State the law and write the formula connecting the electric current flowing through a conductor and voltage applied across it.
(b) In a household five fans each of 100 W are used for 4 hours and an electric press of 500 W for 2 hours every day. Calculate the cost of using the fans and electric press for 60 days if the cost of 1 unit of electrical energy is Rs. 6.5
As shown in the figure below A and B are two lamps. Lamp A is rated at 12 V, 24W. Lamp B is rated at 6.0 V. When lamp B operates at its rated voltage, the current in it is 3.0 A. The values of R1 and R2 are chosen so that both lamps operate at their rated voltages.
Based on the information given, answer the following.
(a) Calculate the current in Lamp A.
(b) State and give reason for the reading of the Voltmeter.
(c) Calculate the resistance of R2.
(d) Find the value of the resistance R1.
(a) Distinguish between ethanol and ethanoic acid experimentally.
Attempt either subpart B or C.
(b) Give the IUPAC name of the first member of Alkene which is formed by addition of conc. sulphuric acid to it. Illustrate the change with the help of a chemical equation.
OR
(c) “All combustion reactions are oxidation but all oxidation reactions are not combustion.” Justify.