### SAT - Science - Physics - Magnetic Effects of Electric Current

#### Question - 1

The direction of magnetic field at the centre of a coil carrying in clockwise direction

• A along the axis of the coil inwards
• B along the axis of the coil outwards
• C perpendicular to the axis
• D none of these

#### Question - 2

For making a strong electromagnet, the material of the core should be

• A Soft iron
• B steel
• C brass
• D laminated steel strips

#### Question - 3

The magnetic lines of force, inside a current carrying solenoid are

• A perpendicular to the axis and equidistance from each other
• B circular and they do not intersect each other
• C along the axis and parallel to each other
• D circular at the ends but are parallel to the axis

#### Question - 4

The direction of the induced current is obtained

• A Fleming's left hand rule
• B Fleming's right hand rule
• C Ampere's rule
• D Maxwell's core screw rule

#### Question - 5

A soft iron bar is introduced inside a current carrying solenoid. The magnetic field inside the solenoid will

• A Le zero
• B remain unaffected
• C decrease
• D increase

#### Question - 6

Magnetic field at the centre of a circular coil of radius r, through which a current I flows is directly proportional to

• A r
• B 1/l
• C l2
• D l

#### Question - 7

A moving charge in a magnetic field has

• A constant velocity
• B constant K.E
• C straight line path
• D none of these

#### Question - 8

A long current carrying wire which is placed near a current carrying coil, the direction of the force acting on PQ will be

• A Parallel to PQ towards P
• B parallel to PQ towards Q
• C perpendicular to PQ towards right
• D perpendicular to PQ towards left

#### Question - 9

A current is flowing in a circular loop of wire in clockwise direction. The magnetic field at the centre of the wire is

• A directed downward
• B zero
• C inversely proportional to the radius of the loop
• D directed upward

#### Question - 10

An electron moving in a circular path of radius r makes n rotates per seconds. The magnetic field produced at the centre has the magnitude

• A zero
• B $\frac { { \mu }_{ 0 }ne }{ 2r }$
• C $\frac { { \mu }_{ 0 }ne }{ 2\pi r }$
• D $\frac { { \mu }_{ 0 }n^{ 2 }e }{ 2r }$