Physics
The presence of a magnetic field at a point can be detected by means of a:
- a strong magnet
- a solenoid
- a compass needle
- a current carrying wire.
Answer
a compass needle
Reason — The presence of magnetic field at a point can be detected by means of a compass needle.
A strong magnet can produce a magnetic field, it doesn't directly detect the presence of a magnetic field. Instead, it creates its own magnetic field.
A solenoid is essentially a coil of wire, which, when current flows through it, generates a magnetic field. It also doesn't directly detect the presence of an external magnetic field. It creates its own magnetic field.
In the presence of a magnetic field, the needle of compass rests only along the direction of magnetic field. Hence, it can be used to detect the presence of a magnetic field.
A current-carrying wire does generate a magnetic field, it doesn't directly detect the presence of an external magnetic field. It's used to create magnetic fields, not to detect them.
Related Questions
In the figure given below, when the key is pressed, a current passes in the wire in the direction from A to B (i.e., from south to north). The north pole of the compass needle will deflect towards:
- East
- North
- South
- West
The strength of a magnetic field depends on :
- magnitude of current
- direction of current
- both (1) and (2)
- none of the above
In the figure given below, current is passed in a downward direction through a cardboard. The magnetic field lines would be :
- straight lines
- concentric circles
- elliptical lines
- squares
The point where two magnetic fields are equal but opposite in direction is called a:
- parallel point
- magnetic point
- pole point
- neutral point