Suppose you have three resistor of (20 Omega),(50 Omega)and (100 Omega) .what minimum and maximum resistances can you obtain from these resistors?

(i) How will you measure the internal resistance of a cell by potentiometer? (ii) A cell supplies a current of 0.9 A through a 1 Omega resistor and a current of 0.3 A through a 2 Omega resistor. Calculate the internal resistance of the cell.

A square loop of side 10 cm and resistance 1 Omega is moved towards right with a constant velocity V_0 as shown in . The left arm of the loop is in a uniform magnetic field of 2 T. the field is perpendicular ot the plane of the drawing and is going into it. the loop is connected to a network of resistors each of value 3 Omega with what speed should the loop be moved so that a steady curfrent of 1 mA flows in the loop.

Suppose, you have two shorts, one is black and the other one is blue, three shirts which are in white, blue and red. You again wish to make different combinations, but you always want to make sure that the shorts and shirt that you wear are of different colours. List and check how many combinations are possible now.

A storage battery of emf 8.0 V and internal resistance 0.5 Omega is being charged by a 120 V de supply using a series resistor of 15.5 Omega . What is the terminal voltage of the battery during charging? What is the purpose of having a series resistor in the charging circuit?

Suppose you have a crop plant with high protein quality, but prone to diseases. If you want to bring the high protein quality and disease resistance in one plant, what type of plant breeding method do you follow? Why?

Water is a universal slvent. But alcohol also dissolves most of the substances soluble in water and also many more. Boiling point of water is 100^(@)C and that of alcohol is 80^(@)C. The specific heat of water is much higher than the specific heat of alcohol. (a) List out three possible differences if instead of water as teh liquid in our body we had alcohol. (b) What value can you derive from this special property of water and its innumerable uses in sustaining life on earth ?

You have two red and two blue blocks. How many different towers can you build that are four blocks high using these blocks ? List all the possibilities.

(a) Given n resistores each of resistance R. how will you combine them to get the (i) maximum (ii) minimum effective resistance? (b) Given the resistances of 1 Omega, 2 Omega, 3 Omega. how will be combine them to get an equivalent resistance of (i) (11//3) Omega (ii) (11//5) Omega, (iii) 6 Omega, (iv) (6//11) Omega ? (c ) Determine the equivalent resistance of networks shown in