How Carey foster bridge is different from meter bridge?

Carey Foster Bridge Advantages The Carey Foster bridge is a modified form of the meter bridge in which the effective length of the wire is considerably increased by connecting a resistance in series with each end of the wire. This increases the accuracy of the bridge.

Which wire is used in Carey foster bridge?

The Carey Foster’s bridge is as in the figure1. One meter long wire of manganin or constantan of uniform cross-section area is stretched along a meter scale.

Why Carey foster is better than meter bridge?

We calculate the resistance of an unknown Resistance (X) using a metre bridge and also with a Carey-Foster Bridge. In excess, we claculate the resistance of the wire used in the bridge and hence get the end-corrections using the Carey-Foster bridge to get a better value of resistance than with the Metre Bridge.

Why we use copper wire in Carey foster bridge?

Ans. The sensitivity and accuracy of a meter bridge is directly proportional to the length of the bridge wire. In Carey Foster Bridge, the effective length of the bridge wire is increased and so it is more accurate and sensitive.

What is sensitivity of meter bridge?

Sensitivity of metre bridge is the accuracy to measure the value of current. bridge is most sensitive when all resistance are of same order.

What is null point in Carey Foster bridge?

The Carey foster bridge principle is simple and similar to Wheatstone’s bridge working principle. It works on the principle of null detection. That means the ratios of the resistances will be equal and the galvanometer records zero where there is no current flow.

What is the application of Carey foster bridge?

In electronics, the Carey Foster bridge is a bridge circuit used to measure medium resistances, or to measure small differences between two large resistances. It was invented by Carey Foster as a variant on the Wheatstone bridge.

What is null point in Carey foster bridge?

In which condition metre bridge is most sensitive?

The meter bridge circuit is most sensitive when all four resistors have similar resistance values.

At what position in a meter bridge do we get maximum sensitivity Why?

The Wheatstone bridge is said to be more sensitive when its voltmeter will be showing 0 deflection, means it will be in a balanced condition, ie., all the four arms are of nearly of same order of magnitude.

Which is better Carey Foster bridge or meter bridge?

1. Aim We calculate the resistance of an unknown Resistance (X) using a metre bridge and also with a Carey-Foster Bridge. In excess, we claculate the resistance of the wire used in the bridge and hence get the end-corrections using the Carey-Foster bridge to get a better value of resistance than with the Metre Bridge. 2.

How is null deflection used on Carey Foster bridge?

This increases the accuracy of the bridge. While performing this experiment, you will balance the Carey Foster bridge by a null deflection method using a galvanometer. You will first determine the resistance per unit length of the material used for the bridge wire, and will then determine the value of an unknown resistance. 6. Experimental Video

How is galvanometer connected to Carey Foster bridge?

The setup consists of a wooden board mounted with a metre long wire on which a jockey can slide which has tap key. The circuit has a Voltage supply of around 3V. The Galvanometer(G) is connected as shown to check the null point. It is protected by a high resistance of around 15000Ω, from very high current ﬂow.

Why are inner ratio arms equal in Carey Foster bridge?

A.It is most sensitive when P,Q,R,S are same or of the same order. Q.Why the resistance for inner ratio arms be equal? A.For increased sensitivity and accuracy. Q.What is the minimum difference in resistances that can be measured by Carey Foster Bridge?