badge image

Enroll For Free Now & Improve Your Performance.

×
User Icon
User Icon
User Icon
User Icon
User Icon

Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Please check your email for login details.
MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
Menu
Grade: 12

                        

Two resistors 400 ohm and 800 ohm are connected in series with a 6V battery. It is desired to measure the current in the circuit. An ammeter of 10 ohm resistance is used for this purpose. What will be the reading in the ammeter? Similarly if a voltmeter of 10,000 ohm resistance is used to measure the potential difference across 400 ohm, what will be the reading of the voltmeter ?

6 years ago

Answers : (3)

Nirmal Singh.
askIITians Faculty
44 Points
							
201-730_7pg (1).jpeg
Regards,
Nirmal SIngh
Askiitians Faculty
6 years ago
Rajbhanu Shukla
24 Points
							
Dear Student
Total resistance of circuit is 400 +800 +10 ohm =1210 ohm (As resistors are connected in series with ammeter)
Current through circuit or each resistor or ammeter will be I = V/R = 0.0049 A = 4.9 x 10-3 A
Now when voltmeter is connected across 400 ohm resistance.
Then total resistance of voltmeter and 400 ohm resistor is

R = 384. 6 ohm
Current I through circuit = = 0.0051 A 6
384/ 6+400
Now let current passes through voltmeter and passes through 400 ohm resistor. I1 I2 V oltage across both
will be same.
So
400 I2 = 10000I1
I1 = 0.04 I2
But
I = I1 +I2
I2 +0.04 I2 = 0.0051
I2 = = 0.0049
0.0051
1.04
THerefore potential differecne across 400 ohm = 400 I2 = 400×0.0049 = 1.95 V
Therefore reading of ammeter = 1.95 V olt
3 years ago
Rishi Sharma
askIITians Faculty
614 Points
							Dear Student,
Please find below the solution to your problem.

Given,
R1 ​= 400Ω, R2 ​= 800Ω
E = 6V
1stCase
r = 10Ω
i = 6/(10 + 400 + 800) ​= 6/(1210) ​= 4.96mA
2ndCase
r = 10000Ω
Req​ = (10000×400)/10400​ + 800 = 30800​/26
i = 6×26/30800​
i 400Ω ​= (25/26​)×(6×26/30800)​
V 400Ω ​= i×400 = 150​×400/30800 = 150/77 ​= 1.95V
Hence option B is the correct answer.

Thanks and Regards
2 months ago
Think You Can Provide A Better Answer ?
Answer & Earn Cool Goodies


Course Features

  • 101 Video Lectures
  • Revision Notes
  • Previous Year Papers
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Test paper with Video Solution


Course Features

  • 110 Video Lectures
  • Revision Notes
  • Test paper with Video Solution
  • Mind Map
  • Study Planner
  • NCERT Solutions
  • Discussion Forum
  • Previous Year Exam Questions


Ask Experts

Have any Question? Ask Experts

Post Question

 
 
Answer ‘n’ Earn
Attractive Gift
Vouchers
To Win!!! Click Here for details