A cell of emf e₁ in the secondary circuit gives null deflection for1.5m length of potentiometer of wire length 10m.If another cell of emf e₂ is connected in series with e₁ then null reflection was obtained for 2.5 m length.Then e₁:e₂

When two unknown resistances are placed in the gaps of meterbridge,the null point is found to be 40cm from one end of the bridge wire.when one of the resistances is shunted with a 10 ohm coil,the null points is 25cm form the same end.The value of each of the unknown resistances is

In a potentiometer experiment, when a resistance of 10 ohm is connected in parallel to the cell in secondary circuit , the balancing length is 350 cm. when 10 ohm resistance is replaced by 20 ohm resistance, the balancing length becomes 420 cm.The internal resistance of the cell in secondary circuit is

When cold junction is at 0⁰C variation of thermo emf(e) of Fe-Cu thermo couple with temperature of hot junction t is given as e=14t-0.02t².Its neutral temperature is

The equation connecting thermo emf with the temperature difference between the junctions 't' of a thermocouple, whose cold junction is maintained at 0⁰C, is given by e = 2040 t - 6.2 t². The neutral and inversion temperatures of the thermocouple in C .ire respectively and nearly equal to:

In a potentiometer using two cells in series gave a balance length 600cm. When the same cells are connected opposing each other then balance length is 100cm. The ratio of emf’s of the cells is

The neutral temperature of a thermo couple is500⁰C.If cold junction is at 30⁰C the inversion temperature is

When an unknown resistance and a resistance of 4Ω are connected in the left and right gaps of a meterbridge, the balance point is obtained at 50cm. The shift in the balance point if a 4Ω resistance is now connected in parallel to the resistance in the right gap is

Four resistors A,B,C and D form a Wheatstones bridge. The bridge is balanced when C = 100Ω .If A and B are interchanged, the bridge balances for C= 121Ω.The value of D is

A potentiometer wire of length 100 cm has a resistance of 10 Ω. It is connected in series with a resistance and a cell of emf 2V and of negligible internal resistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire. The value of external resistance is: