A galvanometer of resistance 50 Ω is connected to a battery of 3 V along with a resistance of 2950 Ω in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
5050 Ω
5550 Ω
6050 Ω
4450 Ω
None of the above
A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will
continue to move due east
move in a circular orbit with its speed unchanged
move in a circular orbit with its speed increased
gets deflected vertically upwards
The magnetic field of a given length of wire carrying a current for a single turn circular coil at centre is B, then its value for two turns for the same wire when same current passing through it is
B/4
B/2
2B
4B
A current carrying coil is subjected to a uniform magnetic field. The coil will orient so that its plane becomes
inclined at 45o to the magnetic field
inclined at any arbitrary angle to the magnetic field
parallel to the magnetic field
perpendicular to magnetic field
Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius r with constant speed v. The time period of the motion is :
Depends on v are not on R
Depends on both R and v
Is independent of both R and v
Depends on R and not on v
The electron enters a region where magnetic field (B) and electric field (E) are mutually perpendicular, then
it will always move in the direction of B
it will always move in the direction of E
it always possess circular motion
it can go undeflected also
A uniform magnetic field acts right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius 2 cm. If the speed of electrons is doubled, then the radius of the circular path will be
2.0 cm
0.5 cm
4.0 cm
1.0 cm
A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is :
B
when a charged particle moving with velocity is subjected to a magnetic field of introduction , the force acting on it is non – zero. This implies that
Angle between is necessarily 90o
Angle between can have any value other than 90o
Angle between can have any value other than zero and 180o
Angle between is either zero or 180o
