Wheatstone bridge and metre bridge — NEET & JEE Questions

Question 1 · difficulty L1 · recall

At balance in a Wheatstone bridge, the current through the galvanometer is

• A. zero
• B. maximum
• C. equal to battery current
• D. independent of resistance ratios

Question 2 · difficulty L2 · understanding

The value of current I in the electrical circuit as given below, when potential at A is equal to the potential at B, will be _______ A.

Question 3 · difficulty L2 · understanding

The value of unknown resistance $$(x)$$ for which the potential difference between $$B$$ and $$D$$ will be zero in the arrangement shown, is :

• A. 3 $$\Omega$$
• B. 42 $$\Omega$$
• C. 6 $$\Omega$$
• D. 9 $$\Omega$$

Question 4 · difficulty L2 · understanding

A battery of $$6 \mathrm{~V}$$ is connected to the circuit as shown below. The current I drawn from the battery is :

• A. 1A
• B. 2A
• C. $$\frac{6}{11}$$ A
• D. $$\frac{4}{3}$$ A

Question 5 · difficulty L2 · understanding

The current I in the given circuit will be :

• A. 10 A
• B. 20 A
• C. 4 A
• D. 40 A

Question 6 · difficulty L2 · understanding

In a meter bridge experiment, for measuring unknown resistance 'S', the null point is obtained at a distance $$30 \mathrm{~cm}$$ from the left side as shown at point D. If R is $$5.6$$ $$\mathrm{k} \Omega$$, then the value of unknown resistance 'S' will be __________ $$\Omega$$.

Question 7 · difficulty L2 · understanding

STATEMENT - 1 In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. and STATEMENT - 2 Resistance of a metal increases with increase in temperature.

• A. Statement - 1 is True, Statement - 2 is True; Statement - 2 is a correct explanation for Statement - 1
• B. Statement - 1 is True, Statement - 2 is True; Statement - 2 is NOT a correct explanation for Statement - 1
• C. Statement - 1 is True, Statement - 2 is False
• D. Statement - 1 is False, Statement - 2 is True

Question 8 · difficulty L3 · understanding

If the potential difference between $\mathrm{B}$ and $\mathrm{D}$ is zero, the value of $x$ is $\frac{1}{n} \Omega$. The value of $n$ is __________.

Question 9 · difficulty L3 · understanding

A Wheatstone bridge is initially at room temperature and all arms of the bridge have same value of resistances ($R_1 = R_2 = R_3 = R_4$). When $R_3$ resistance is heated to some temperature, its resistance value has gone up by 10%. The potential difference ($V_a - V_b$) (after $R_3$ is heated) is _________ V.

• A. 1.05
• B. 0.95
• C. 0
• D. 2

Question 10 · difficulty L3 · understanding

A wire of length $$10 \mathrm{~cm}$$ and radius $$\sqrt{7} \times 10^{-4} \mathrm{~m}$$ connected across the right gap of a meter bridge. When a resistance of $$4.5 \Omega$$ is connected on the left gap by using a resistance box, the balance length is found to be at $$60 \mathrm{~cm}$$ from the left end. If the resistivity of the wire is $$\mathrm{R} \times 10^{-7} \Omega \mathrm{m}$$, then value of $$\mathrm{R}$$ is :

• A. 63
• B. 70
• C. 66
• D. 35