please answer all of them they are from meter bridge experiment class 12 2 If the metre bridge - Physics - Current Electricity

Question

please answer all of them they are from meter bridge experiment
class 12
2 If the metre bridge wire is not of uniform area of cross
section,

how will it affect the observations?
Fig E 2 3 Defective scale of a metre bridge
3 If the metre bridge wire is not made of a material of uniform
density,
how will it affect the observations?
4 If the same experiment is performed with AC = 50 cm wire
instead
of 1 m, what changes would be there in the result?
5 The scale attached along the wire may not indicate the
exact
length as shown in Fig E 2 3 How would you minimise the
error?
6 Why is the metre bridge not suitable for measuring very
high/very low resistances?
7 Why is the metre bridge preferred for determining the
resistanceof a wire over the Ohms law circuit

Rajnish Singh · Accepted Answer

2> if meter bridge is not uniform cross section than the area
changes across the length of the wire and hence the resistance
changes and metre bridge resistance in effective the observation is
not not possible since the metre bridge works on the principle of
wheatstone bridge and since reistance ratio cant be comes equal due
to change in resiatance no null point can be found

3> the uniform density of material is necessary for the accuracy
of metre scale , due to change in mass per per unit length its
restivity and hence the resistance changes over its length, which
gives error in observation

4> we can take the length 50 cm we can take it 50cm and carry
out observation (no change in value of observation)

5> to minimise the error we must tight the wire along the meter
scale so to minimise the error

6> the metre scale cannot be used for high value of resistance
because it becomes insensitive for too high resistance

7> metre bridge is preferred because it works on the null
deflection method and gives most accurate result