magnetism

The pointer of a galvanometer stops at a certain reading when the torsion in the two spring coils .......... The magnetic torque acting on the coil.

• Is greater than

• Equals

• Is less than

• Is in the same direction as

In a sensitive galvanometer,which of the following when decreased,the sensitivity of the galvanometer in measuring and electric current intensity increases?

• The number of turns of the galvanometer coil

• The area of the galvanometer coil

• The magnetic field strength of the used magnet

• The torsional constant of the two spring wires

Two circular coils P and Q are made from similar wires but the radius and current of coil P is twice that of Q, if the magnetic flux density at their centers is the same, so the ratio between potential difference across circular coil P and the potential difference across circular coil

• 1:1

• 2:1

• 4:1

• 8:1

A solenoid is connected to a battery in a closed circuit, if It's turns are compressed regularly. The ,magnetic flux density at a point on its axis inside it will..........

• Increase

• Decrease

• Remain constant

• Vanish

The torque acting on a coil through which an electric current is flowing and placed in a magnetic field vanishes when the coil plane is makes ..........

• An angel of 45 with field

• An angel of 30 with field

• An angel of 60 with field

• An angel of 90 with field

The resultant of the torque acting on the coil of the galvanometer when it's pointer became stable at a certain reading is equal to ......

• BIAN

• 2BIAN

• Zero

When the intensity of the current passing through the coil of the galvanometer is doubled, the sensitivity of the device will .......

• Remain constant

• Increase to double

• Decrease to half

• Increase to 4 times

When the circuit connected to the coil of the galvanometer is opened, the part responsible for returning the pointer to zero is ........

• Concave polse

• Agate spring

• Pair of spring coils

• Soft iron core

The ratio between ammeter resistance to resistance of the shunt inside it is .......one

• More than

• Less than

• Equals

When the shunt resistance is connected to the coil of the galvanometer, the device sensitivity will......

• Increase

• Decrease

• Constant