FBISE, NCP & NBF-aligned resources for Classes 9–12
Browse by Class
Browse by Type
Physics Chapter 11 : Topic 15
Galvanometer and Null Methods
1 / 30
The main function of a galvanometer in a null method is to:
Reasoning: In null methods, a galvanometer is used as a sensitive detector to identify the condition when current becomes zero.
2 / 30
A galvanometer shows zero deflection in a null method when:
Reasoning: Zero deflection indicates that no current flows through the galvanometer because both points are at the same potential.
3 / 30
The use of a galvanometer in a potentiometer is based on the principle of:
Reasoning: A galvanometer detects the balance point where no current flows through it.
4 / 30
A galvanometer is preferred in null methods because it is:
Reasoning: Galvanometers can detect very small currents, making them suitable for accurate measurements.
5 / 30
In a potentiometer experiment, zero galvanometer deflection indicates that:
Reasoning: At balance point, the potential difference across the galvanometer is zero.
6 / 30
The condition of zero current through a galvanometer is called:
Reasoning: A null condition means the detector shows zero response.
7 / 30
In a null method, the galvanometer should ideally have:
Reasoning: Higher sensitivity allows detection of very small currents and accurate balance points.
8 / 30
When a galvanometer shows deflection in a potentiometer circuit, it means:
Reasoning: Deflection occurs because current flows due to an existing potential difference.
9 / 30
The main advantage of using a galvanometer in a null method is that it:
Reasoning: At balance, no current flows through the galvanometer, preventing measurement errors.
10 / 30
A galvanometer is connected between two points in a potentiometer. At balance, the potential difference between these points is:
Reasoning: Equal potentials at the two points produce no current through the galvanometer.
11 / 30
The sensitivity of a galvanometer refers to its ability to:
Reasoning: A sensitive galvanometer gives noticeable deflection for very small currents.
12 / 30
In a null method, the galvanometer acts as:
Reasoning: It only indicates whether the circuit has reached the balanced state.
13 / 30
If the galvanometer in a potentiometer shows a deflection, the jockey should be:
Reasoning: The jockey is moved until the point of zero galvanometer deflection is found.
14 / 30
If the galvanometer deflects to one side, it indicates:
Reasoning: Deflection direction shows the direction of current through the galvanometer.
15 / 30
Reversing the connections of a galvanometer will:
Reasoning: Reversing polarity reverses the current direction and hence the deflection direction.
16 / 30
A galvanometer in a null method is not used to measure:
Reasoning: It only detects small currents; it is not used as an accurate current measuring device in null methods.
17 / 30
In a potentiometer, the galvanometer is connected between:
Reasoning: At balance, both points connected to the galvanometer have the same potential.
18 / 30
A galvanometer gives zero deflection because:
Reasoning: Deflection of the galvanometer coil requires current flow.
19 / 30
The accuracy of a potentiometer measurement depends on a galvanometer having:
Reasoning: A sensitive galvanometer locates the exact balance point.
20 / 30
In a null method, the measurement is made when the galvanometer reading is:
Reasoning: The null condition occurs when the detector shows no deflection.
21 / 30
The galvanometer in a potentiometer experiment protects the cell being measured from:
Reasoning: Since no current is drawn at balance, the cell is not loaded.
22 / 30
A moving coil galvanometer works because a current-carrying coil experiences:
Reasoning: Current in a magnetic field produces torque that causes coil deflection.
23 / 30
In a balanced potentiometer circuit, the galvanometer resistance affects:
Reasoning: At null condition, no current flows through the galvanometer, so its resistance does not affect the result.
24 / 30
The galvanometer is called a null detector because it:
Reasoning: Its purpose is to identify when the current becomes zero.
25 / 30
In a Wheatstone bridge experiment, the galvanometer is used to:
Reasoning: The galvanometer indicates when the potential difference between two points becomes zero.
26 / 30
If the galvanometer is replaced by an ordinary ammeter in a null method:
Reasoning: An ammeter is not sensitive enough to detect very small currents.
27 / 30
A very small deflection of a galvanometer indicates:
Reasoning: Small current through the galvanometer results from a small potential difference.
28 / 30
The use of a galvanometer in null methods improves accuracy because:
Reasoning: The null method compares potentials without drawing current from the source being tested.
29 / 30
In a potentiometer, if the galvanometer shows zero deflection at $\mathbf{80\ cm}$, this length represents:
Reasoning: The length at which the galvanometer shows no deflection is called the balancing length.
30 / 30
The most important characteristic of a galvanometer used in null methods is:
Reasoning: High sensitivity allows detection of extremely small currents required for accurate null measurements.
Your score is
Restart quiz
