The resistance of the three arms of the balanced wheat stone bridge is 50 ohms. The resistance in the 4 ohm range is:
Correct answer: B. 50 ohm
- A. 25 ohm
- B. 50 ohm
- C. 75 ohm
- D. 100 ohm
Explanation
In a balanced Wheatstone bridge, the ratio of the resistances in one arm is equal to the ratio of the resistances in the other arm, expressed as X = (R * Q) / P. With all three known resistances being 50 ohms, the unknown resistance X also calculates to be 50 ohms, thereby maintaining the balance. The other options do not satisfy this relationship and would unbalance the bridge.
This question appeared on the ETEA MDCAT 2006 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Resistance and Resistivity
Resistance measures opposition to current in a conductor and follows R = V/I for an ohmic conductor, while resistivity is an intrinsic property of the material. Questions use R = ρL/A, examine effects of length, cross-sectional area and temperature, and distinguish resistance, resistivity, conductance and conductivity.
Practise Current Electricity
1,053 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Resistance and Resistivity questions
The unit of conductance is
The effective resistance between the points A and B in the figure is
A carbon resistor connected to a battery of 50V and 2A current is passing through it. If voltage is increased to 75V then current will be:
Ohm's law is valid only for currents following in:
A 50Ω resistance wire is stretched such that its length is doubled and its cross section area becomes half. The new resistance is:
An efficient voltmeter has: