Kirchhoffs laws and applications, Wheatstone bridge, metre bridge - One Line Questions
1.
In a Wheatstone bridge, if P=3Ω, Q=6Ω, R=4Ω, and S=8Ω, what is the ratio P/Q and R/S? —
0.5 and 0.5
2.
The condition for a Wheatstone bridge to be balanced is P/Q = R/S, where P, Q, R, and S are resistances. If P=2Ω, Q=4Ω, and R=6Ω, what is the value of S for balance? —
12Ω
3.
In a metre bridge experiment, if the jockey is at the 40 cm mark from the left end and the galvanometer shows no deflection, and the known resistance in the right gap is 10Ω, what is the unknown resistance in the left gap? —
15Ω
4.
In a metre bridge, if the known resistance is R and the balancing length is l, the unknown resistance X is given by X = R * (l / (100 - l)). If R = 50Ω and l = 60 cm, what is X? —
75Ω
5.
The metre bridge works on the principle of the Wheatstone bridge and is used to determine an unknown resistance by comparing it with: —
A standard known resistance
6.
The jockey in a metre bridge is used to: —
Find the null point on the wire
7.
The sensitivity of a Wheatstone bridge is highest when: —
The resistances are comparable
8.
In Kirchhoff's second law, the algebraic sum of potential differences (voltage drops and rises) around any closed loop in a circuit is: —
Zero
9.
Which component is crucial for detecting the null point in both Wheatstone bridge and metre bridge? —
Galvanometer
10.
Why is a galvanometer used instead of an ammeter in a Wheatstone bridge to detect balance? —
Ammeters measure current, galvanometers detect very small currents.
11.
Which law is fundamentally applied when analyzing the potential drop across resistors in a closed loop according to Kirchhoff's second law? —
Conservation of Energy
12.
Kirchhoff's junction rule is applicable to: —
Only junctions where currents meet
13.
Kirchhoff's loop rule is applicable to: —
Any closed electrical path (loop)
14.
In applying Kirchhoff's laws, the choice of direction for current in a loop is: —
Arbitrary; the final result will be correct regardless
15.
In a Wheatstone bridge, if the galvanometer shows deflection, it means the bridge is: —
Unbalanced
16.
If the unknown resistance in a metre bridge is very high, the balancing length 'l' will be: —
Close to 100 cm
17.
If the unknown resistance in a metre bridge is very low, the balancing length 'l' will be: —
Close to 0 cm
18.
Kirchhoff's second law (loop rule) is a consequence of which fundamental law? —
Conservation of Energy
19.
Kirchhoff's first law (junction rule) is a consequence of which fundamental law? —
Conservation of Charge
20.
The resistance wire used in a metre bridge is typically made of: —
Manganin or Nichrome
21.
For a Wheatstone bridge to be balanced, the ratio of resistances in the two arms must be: —
Equal
22.
Consider a junction with three incoming currents I1, I2, I3 and two outgoing currents I4, I5. Kirchhoff's first law states: —
I1 + I2 + I3 = I4 + I5
23.
What happens to the current through the galvanometer in a Wheatstone bridge if the battery voltage is increased? —
It increases (if unbalanced)
24.
The metre bridge is preferred over the Wheatstone bridge for measuring moderate resistances because: —
It is simpler to construct and use for moderate values.
25.
Which of the following is a disadvantage of using a metre bridge? —
It has limited accuracy due to the resistance of the end connections
26.
A metre bridge is a practical application of which principle? —
Wheatstone bridge
27.
In a balanced Wheatstone bridge, the current through the galvanometer is: —
Zero
28.
If in the metre bridge experiment, the balancing length is found to be very small (e.g., 5 cm), it implies that the unknown resistance is: —
Much smaller than the known resistance
29.
When applying Kirchhoff's second law, if we traverse a loop in the opposite direction of the current through a resistor, the potential difference is taken as: —
Positive
30.
If we traverse a loop in the direction of the emf source (from negative to positive terminal) while applying Kirchhoff's second law, the emf is taken as: —
Positive
31.
A complex circuit can be simplified and analyzed using: —
Kirchhoff's laws
32.
A Wheatstone bridge circuit has four resistors P, Q, R, and S, and a galvanometer G. If the bridge is balanced, which of the following is true? —
P*S = Q*R
33.
When applying Kirchhoff's second law, if we traverse a loop in the direction of the current through a resistor, the potential difference is taken as: —
Negative
34.
If we traverse a loop in the opposite direction of the emf source (from positive to negative terminal) while applying Kirchhoff's second law, the emf is taken as: —
Negative
35.
A galvanometer deflects to the right when current flows in a certain direction. If the galvanometer in a Wheatstone bridge deflects to the right when the jockey is moved towards the right end of the wire, what does this indicate about the potential? —
Potential at the left end is higher than the right end.
36.
According to Kirchhoff's first law, the algebraic sum of currents entering a junction is equal to: —
The algebraic sum of currents leaving the junction
37.
A galvanometer with resistance G is connected in series with a Wheatstone bridge. If the bridge is balanced, the current through G is zero. What happens if G is increased? —
The balance condition changes.
38.
In a Wheatstone bridge, if the resistance of one arm is increased significantly, what is the likely effect on the balance condition? —
The balance point will shift.
39.
Which of the following is NOT a condition for applying Kirchhoff's laws? —
The circuit must be a DC circuit.
40.
The formula P/Q = R/S for a balanced Wheatstone bridge assumes: —
The galvanometer has a finite, non-zero resistance.
41.
In a metre bridge experiment, the unknown resistance is placed in: —
The right gap
42.
Which of the following statements best describes Kirchhoff's second law? —
The sum of voltages around a closed loop is zero.
43.
In a parallel circuit with branches having resistors R1, R2, and R3, Kirchhoff's first law applied at a junction states that the total current entering the junction is equal to: —
The sum of currents flowing through R1, R2, and R3
44.
If the jockey is moved along the wire in a metre bridge, the resistance of the wire segment changes. This change in resistance causes a change in: —
The potential difference across the galvanometer
45.
A Wheatstone bridge is used to measure: —
Unknown resistance
46.
The end resistances of the metre bridge connections can be minimized by: —
Ensuring all connections are tight and clean, and using a four-way key
47.
A metre bridge is most accurate when the unknown resistance is: —
Of the order of the resistance of the bridge wire
48.
If the balancing length for an unknown resistance 'X' in a metre bridge is 'l', and the total length of the wire is 100 cm, the resistance of the wire per unit length is assumed to be uniform. The formula to calculate X is: —
X = R * (l / (100 - l))
49.
Consider a circuit with three resistors R1, R2, and R3 connected in series to a battery. According to Kirchhoff's second law, the sum of voltage drops across R1, R2, and R3 will be equal to: —
The total emf of the battery