Five equal resistances each of resistance R are connected as shown in the figure.  A battery of 4V  is connected between A and B.  The current flowing in AFCEB will be

Two batteries of emf 4V and 8V with internal resistance are connected in a circuit with a resistance of as shown in figure.  The current and potential difference between the point P and Q are

Fuse wire is a wire of

Three equal resistors connected in series across a source of emf together dissipate 10 W of power.  What will be the power dissipated in watt if the same resistors are connected in parallel across the same source of emf ?

The temperature of inversion of a thermocouple is 620^o C and the neutral temperature is 300^o C.  What is the temperature of cold junction ?

n resistances each of r ohm, when connected in parallel give an equivalent resistance of R ohm.  If these resistances were connected in series, the combination would have a resistance in ohms, equal to

A storage battery is connected to the mains for charging with emf of 12.5 V. The internal resistance of the storage battery is 1 Ω. When the charging current is 0.5 A, the potential difference across the storage battery is

You are given several identical resistances each of value and each capable of carrying a maximum current of one ampere.  It is required to make a suitable combination of these resistances of which can carry a current of 4 A.  The minimum number of resistances of the type R that will be required for this job is