| ⇦ | 
| ⇨ |
A potentiometer wire of length 100cm has a resistance of 10Ω. It is connected in series with a resistance and a cell of emf 2V having negligible internal reistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire.The value of external resistance is
Options
(a) 760Ω
(b) 640Ω
(c) 790Ω
(d) 840Ω
Correct Answer:
790Ω
Explanation:
No explanation available. Be the first to write the explanation for this question by commenting below.
Related Questions: - If h is the height of the capillary rise and r be the radius of capillary tube,
- A thermodynamic system undergoes cyclic process ABCDA as shown in figure
- One mole of an ideal gas at an initial temperature of T K, does 6R joule of work
- When a bullet of mass 10 g and speed 100 ms⁻¹ penetrates up to distance 1 cm
- An inclined plane makes an angle of 30° with the horizontal.A solid sphere
Topics: Current Electricity
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- If h is the height of the capillary rise and r be the radius of capillary tube,
- A thermodynamic system undergoes cyclic process ABCDA as shown in figure
- One mole of an ideal gas at an initial temperature of T K, does 6R joule of work
- When a bullet of mass 10 g and speed 100 ms⁻¹ penetrates up to distance 1 cm
- An inclined plane makes an angle of 30° with the horizontal.A solid sphere
Topics: Current Electricity (136)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Let the resistance be r and current be I .According to loop rule :
E=V+Ir
2=I(10+r)
And also
I*(40/100)=0.01V
Here you get I=2.5*10^-3ampere
Put this Vue in eqn 2=I(10+r) and get solution