You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard VII

Physics

Symbols of Electric Components

state the cha...

Question

state the change in ammeter reading observed when a resistance wire in a circuit is replaced by a wire of same material and same length but comparatively double cross-sectional area keeping the source of potential difference constant.

Open in App

Solution

As we know ,
$R = ρ \frac{l}{A} I f A' = 2 A t h e n, R' = \frac{R}{2} s o r e s i s \tan c e i s r e d u c e d b y h a l f . A s, V = I R S o f o r c o n s \tan t v o l t a g e, \frac{V}{R} = I A s R i s r e d u c e d t o h a l f s o c u r r e n t i s t h e c i r c u i t g e t s d o u l b e d a s r e s i s \tan c e i s i n v e r s l y p r o p o r t i o n a l t o c u r r e n t .$

Suggest Corrections

Similar questions

In a simple circuit containing a cell, an ammeter, aclosed key and a nichrome wire of length 'l', what changes (if any) would be observed in ammeter reading, if the nichrome wire is replaced by a silver wire of length 'l' and same thickness?

Q. In the given circuit diagram, two resistance wires

A

and

B

are of same area of cross-section and same material, but

A

is longer than

B

. Which ammeter

A_{1}

A_{2}

will indicate higher reading for current? Give reason.

Q. In the circuit diagram shown, the two resistance wires A and B are of same area of cross section and same material, but A is longer than B. Which ammeter

A_{1}

A_{2}

will indicate higher reading for current? The answer is

A_{x}

then x is

There are two wires, A and B, made of same material. Both the wires have the same length. It is observed that the resistance of wire A is four times the resistance of wire B, then find the ratio of their cross sectional areas.

Q. The resistance of a wire of cross-section '

a

' and length '

l

' is

R

o h m

. The resistance of another wire of the same material and of the same length but cross-section '

4 a

' will be

Join BYJU'S Learning Program

state the change in ammeter reading observed when a resistance wire in a circuit is replaced by a wire of same material and same length but comparatively double cross-sectional area keeping the source of potential difference constant.

As we know , R =ρlAIf A' = 2 Athen ,R' = R2so resistance is reduced by half.As,V = I RSo for constant voltage,VR= IAs R is reduced to half so current is the circuit gets doulbed as resistance is inversly proportional to current.