physics : class12 Galvanometer Function : Potentiometer : Current Electricity MCQ Questions and Answers
Practice important
Galvanometer Function
MCQ questions and answers.
Page 2
of
2
|
20
MCQ Questions
1. What is the main function of a galvanometer in a potentiometer circuit?
A.
To detect the presence of current
B.
To supply electrical energy
C.
To measure resistance directly
D.
To maintain constant temperature
Correct Answer:
To detect the presence of current
Explanation:
The galvanometer detects whether current flows through the circuit connected to it, especially while locating the balance point.
2. In a potentiometer, the galvanometer shows zero deflection when the potential difference across it is:
A.
Maximum
B.
Zero
C.
Equal to the total emf of the cell
D.
Twice the potential difference of the wire
Correct Answer:
Zero
Explanation:
Zero galvanometer deflection indicates that no current flows through it, so the potential difference across its terminals is zero.
3. The point on the potentiometer wire where the galvanometer shows zero deflection is called the:
A.
Heating point
B.
Null or balance point
C.
Current point
D.
Resistance point
Correct Answer:
Null or balance point
Explanation:
The position of zero galvanometer deflection is known as the null point or balance point.
4. What does a deflection of the galvanometer indicate in a potentiometer experiment?
A.
No potential difference exists
B.
A potential difference exists between its terminals
C.
The potentiometer wire is broken
D.
The cell has no emf
Correct Answer:
A potential difference exists between its terminals
Explanation:
A galvanometer deflects when current passes through it, which occurs when a potential difference exists across its terminals.
5. Why is a galvanometer used while finding the balance point in a potentiometer?
A.
To indicate the point where current through it becomes zero
B.
To increase the current in the potentiometer wire
C.
To provide the potential gradient
D.
To act as the battery
Correct Answer:
To indicate the point where current through it becomes zero
Explanation:
The galvanometer helps identify the balance point by showing zero deflection when no current flows through it.
6. If the galvanometer deflects to the right when the jockey touches a point on the potentiometer wire, what can be concluded?
A.
Current flows through the galvanometer in one direction
B.
The balance point has certainly been reached
C.
No current flows anywhere in the circuit
D.
The galvanometer is disconnected
Correct Answer:
Current flows through the galvanometer in one direction
Explanation:
The direction of galvanometer deflection indicates the direction of current through the galvanometer.
7. When the jockey is moved beyond the balance point, the galvanometer deflection generally:
A.
Remains in the same direction without change
B.
Reverses direction
C.
Becomes permanently zero
D.
Makes the battery stop working
Correct Answer:
Reverses direction
Explanation:
At the balance point the deflection is zero; moving the jockey to the other side changes the polarity of the potential difference and reverses the deflection.
8. In a potentiometer, the galvanometer is connected between the jockey and the:
A.
Terminal of the resistance wire or test circuit
B.
Earth only
C.
Switch casing
D.
Insulating support only
Correct Answer:
Terminal of the resistance wire or test circuit
Explanation:
The galvanometer forms a connection between the jockey and the other point of the circuit whose potential is being compared.
9. At the null point of a potentiometer, the galvanometer acts as an indicator of:
A.
Equal potential at its terminals
B.
Maximum current in the wire
C.
Maximum resistance in the circuit
D.
The temperature of the wire
Correct Answer:
Equal potential at its terminals
Explanation:
Zero galvanometer deflection shows that its two terminals are at the same potential at the null point.
10. Which observation confirms that the balance point has been located in a potentiometer experiment?
A.
The galvanometer gives maximum deflection
B.
The galvanometer shows zero deflection
C.
The galvanometer becomes hot
D.
The galvanometer needle remains permanently at one end
Correct Answer:
The galvanometer shows zero deflection
Explanation:
The balance point is confirmed when the galvanometer shows zero deflection, indicating no current through it.