Describe an experiment to determine to determine the temperature co-efficient of a thermistor using a meter bridge.

Explanation

Formula `alpha = ( 2.303 ( log R _(1) - log R _(2)))/( T _(1) - T _(2)) and R = ( Sl )/( 1-l ) Omega `

Ba-Battery
K- Plug key
S - Resistance box
G - Galvanometer
Procedure : The connections are made as shown in the circuit diagram. Suitable resistance S is unplugged in the standard resistance box.
The circuit is checked for opposite deflections by placing the slider at the two ends of the wire A & C. The thermistor is immersed in a beaker containing hot water.
The slider is moved on the wire from the end A towards C till the galvanometer shown zero deflection at the point D, the balancing length l is measured.
The corresponding temperature of the hot water is noted as `t_(1) ^(0) C (T_(1) = 273 + t _(1))`
The resistance of thermistor `R_(1) at T_(1)` is calculated using the formula `R_(1) = Sl//1-l.` The experiment is repeated when the temperature of water decrease by a small value (about `5^(@)C)` and the corresponding resistance `R_(2)` is calculated.
The temperature co-efficient of thermistor is calculate using formula
`alpha = ( 2.303 ( log R_(1) - log R _(2)))/( T _(1) - T _(2))`