# Obj-1 HC Verma Magnetic Field due to a Current Solutions Vol-2 Class-12 Ch-35

Obj-1 HC Verma Magnetic Field due to a Current Solutions Vol-2 Class-12 Ch-35 Concept of Physics for Class-12. Step by Step Solutions of Objective -1 (MCQ-1) Questions of Chapter-35 Magnetic Field due to a Current (Concept of Physics) .Visit official Website CISCE for detail information about ISC Board Class-11 Physics.

## Obj-1 HC Verma Magnetic Field due to a Current Solutions Vol-2 Class-12 Ch-35

 Board ISC and other board Publications Bharti Bhawan Publishers Chapter-35 Magnetic Field due to a Current Class 12 Vol 2nd writer HC Verma Book Name Concept of Physics Topics Solution of Objective-1 (MCQ-1) Questions Page-Number 248, 249

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Exercise

### HC Verma Solutions of Ch-35 Vol-2 Concept of Physics for Class-12

(Page-248)

#### Question-1 :-

A vertical wire carries a current in upward direction. An electron beam sent horizontally towards the wire will be deflected

(a) towards right

(b) towards left

(c) upwards

(d) downwards.

The option (c) upwards is correct
Explanation:

According to the right-hand thumb rule, A vertical wire is carrying current in upward direction, so the magnetic field produced will be anticlockwise. As the electron beam is sent horizontally towards the wire, the direction of the current will be horizontally away from the wire (direction of conventional current is opposite to the direction of the negative charge). According to Fleming’s left-hand rule, the force will act in upward direction, deflecting the beam in the same direction.

A proton beam is going from north to south and an electron beam is going from south to north. Neglecting the earth’s magnetic field, the electron beam will be deflected

(a) towards the proton beam

(b) away from the proton beam

(c) upwards

(d) downwards

The option (a) towards the proton beam is correct
Explanation:

A proton beam is going from north to south, so the direction of the current due to the beam will also be from north to south. Also, an electron beam is going from south to north, so the direction of the current due to the beam will also be  from north to south. The direction of conventional current is along the direction of the flow of the positive charge and opposite to the flow of the negative charge.

The option (b) move towards the wire is correct
Explanation:

Force acting on the wire per unit length carrying current i2 due to the wire carrying current i1 placed at a distance d is given by

So, forces per unit length acting on sides AB and CD are as follows:

Here, FAB > FCD  because force is inversely proportional to the distance from the wire and wire AB is closer to the wire carrying current i1.
The forces per unit length acting on sides BC and DA will be equal and opposite, as they are equally away from the wire carrying current i1, with current i2 flowing in the opposite direction.
∴ FBC = – FDA

Now,
Net force :

Hence, the loop will move towards the wire.

#### Question 7:-

A moving charge produces

(a) electric field only

(b) magnetic field only

(c) both of them

(d) both of them

The option (c) both of them is correct
Explanation:

Because of the presence of a charge, a particle produces an electric field.

Also, because of its motion, that is, the flow of charge or current, there is generation of a magnetic field.

Magnetic field will be independent of the motion of the observer because the velocity with which the observer is moving is comparable to drift velocity of electron which is very small as compared to the speed of flow of current from one end of wire to other end. So it can be neglected  and hence, magnetic field due to the wire w.r.t the observer will be

B =

—: End of Magnetic Field due to a current Obj-1 HC Verma (MCQ-1)  Solutions Vol-2 Chapter-35 :–