Q.

Three resistors R1, R2,and R3, are connected in parallel and the combination is connected to a battery, ammeter, voltmeter, and key.


Question Image

Which of the following the expression used for find the equivalent resistance of the combination of the resistors.


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

1R=1R1+1R2+1R3

b

R=R1+R2+R3

c

R=R1R2

d

R=R1-R2 

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The expression for equivalent resistance of three resistors R1,R2 and R3 connected in parallel is
1/R1+1/R2+1/R3 It is discovered that the total current I is the sum of the individual currents flowing through each branch of the combination.  For example, if three resistors are connected in parallel via voltage source V, then the total current in the circuit (I) is-
=>I=I1+I2+I3   ……………………….. (i)  [I= total current in the circuit]
When we apply Ohm's law to each resistor, we get
I1=V/R1  [I1= current in first resistance; V=voltage; R1=first resistance]….(ii)
I2=V/R2  [I2=current in second resistance; V=voltage; R2=second resistance]..(iii)
I3=VR3   [I3= current in third resistance; V=voltage; R3=third resistance]….(iv)
Put the values of equations (ii),(iii) and (iv) in equation (i) we get
VRp=VR1+VR2+VR3 VRp=V[1R1+1R2+1R3]
1Rp=1R1+1R2+1R3
   
Watch 3-min video & get full concept clarity

tricks from toppers of Infinity Learn

score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon
Three resistors R1, R2,and R3, are connected in parallel and the combination is connected to a battery, ammeter, voltmeter, and key.Which of the following the expression used for find the equivalent resistance of the combination of the resistors.