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

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.

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