In a meter bridge experiment, the null point divides the wire as 30 cm and 70 cm. If known resistance is 6 Ω, the unknown is:
A2.57 Ω
B6 Ω
C18 Ω
D14 Ω
Answer & Solution
Correct answer: D. 14 Ω
Meter bridge ratio: R_unknown / R_known = (100 - l)/l where l = 30 cm. So R_unknown = 6 × (70/30) = 6 × 7/3 = 14 Ω.
Related questions
For a battery of emf ε and internal resistance r driving current I through external resistA galvanometer of resistance G is converted into a voltmeter reading full-scale voltage V A galvanometer of resistance G shows full-scale deflection at current I_g. To convert it iThe relation between current density j, drift velocity v_d, number density n and charge e A wire has a resistance R. It is stretched uniformly so that its length becomes 2L. The neKirchhoff current law at a junction is a statement ofTwo cells of emf ε and internal resistance r each are connected in parallel. The equivalenA potentiometer of length L is used to compare emfs. If the balance lengths for cells of e