## Electric Charges and Magnetic field:

1. The charge moving perpendicular to the magnetic field experiences
a. max force
b. minimum force
c. no force
d. none

2. Which of the following is correct
a. 1T= 103G
b. 1T=104 G

c. 1T=10-4G
d. none

3. Which one of the following is not deflected by magnetic field
a. alpha
b. beta

c. neutrons
d. none

4. The direction of magnetic force on a current carrying conductor is given by the rule known as
a. right hand grip
b. right hand palm
c. Flemming rule
d. all

5. Magnetic field inside a solenoid is
a. zero
b. minimum
c. max
d. none

6. A charge moving in uniform magnetic field penetrates a layer of lead and looses one-half of kinetic energy. the radius of curvature chafes to
a. twice the original value
b. 1/√2
c.half the original value
d. none

7. A proton moving with a velocity of 2*106m/s describes a circle of radius R in a magnetic field. what will be the speed of alpha particles to describe a circle of same radius in the same magnetic field
a. 106 m/s
b. 2*106 m/s
c. 4*106m/s
d. 8*106m/s

8. The magnetic induction at the center of a solenoid id B. if the length of solenoid is reduced to half and the same wire is wound over it in two layers. then the new magnetic induction is
a. B
b. B/2
c. 2B
d, 4B

8. When a charged particles enter in uniform magnetic field, its kinetic energy
a. remains constant
b. decrease
c. increase
d. becomes zero

9. If a electron describes half a revolution in a circle of radius R in a magnetic field B ,the energy acquired by it is
a. zero
b. 1/2 mv2
c. 1/4 mv2
d. lambda rB electron volt

10. Two straight wires are set parallel to each other.each carries a current I in the same direction and separation between them is 2R . the intensity of magnetic field at a distance R between two wires is
a. I/R
b. 2I/R
c. 4I/R
d. zero

11. A long solenoid  carrying a current I produces a magnetic field B along its axis. if the current is doubled and the number of turns per cm is hived, the new value of magnetic field is
a. B
b. 4B
c. 2B
d. B/2

12. A proton and alpha particle moving with the same velocity enter into a uniform magnetic field , the  ratio of radii of circular paths described by the proton and aloha particle is
a. 1:2
b. 1:4
c. 1:16
d. 4:1

13. An electron is traveling along X direction . it encounters a magnetic field in the Y direction . its subsequent motion will be
a. straight line along X direction
b. a circular in XZ plane
c. a circular in yz plane
d. a circular in xy plane

14. A charged particle is at the rest at the region where magnetic field and electric field are parallel. the particle will move in
a. a straif=ght line
b. ellipse
c. circle
d. none

15. When a charged particle enters the uniform magnetic field, its kinetic energy
a. remains constant
b. increases
c. decreases
d. becomes zero

16.  A proton and a Due-tron is moving with equal velocities perpendicular to a uniform magnetic field. a Due-tron has the same energy as the proton but has twice its mass. the ratio of the magnetic force on the proton to that of the neutron is
a. 0.
b.1
c. 2
d. 4

17. A proton with initial kinetic energy E is moving in a circular motion in a uniform magnetic field. when it has completed one eighth of a revolution . \,what is its kinetic energy
a. 1.4E
b. 0.71E
c. E
d. E/4

18. A 2.0 m wire segment  carrying a current of 0.60A oriented parallel to a uniform magnetic field of 0.50T experiences a force of what magnitude
a. 6.7 N
B. 0.30N
C. 0.15N
D.ZERO

Thanks.