Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Two parallel plates separated by a distance of 5mm are kept at a potential difference of 50 V. A particle  of mass   and charge   enters in it with a velocity .  The acceleration of the particle will be

(a)

(b)

(c)

(d) 2

The variation of anode current in a triode corresponding to a change in grid potential at three different values of the plate potential is shown in the diagram. The mutual conductance of the triode is

(a) 2.5 m mho

(b) 5.0 m mho

(c) 7.5 m mho

(d) 10.0 m mho

  energy. The emitted particle is

(a) Neutron

(b) Proton

(c) α - particle

(d) Neutrino

Magnetic meridian is:

1. A point.
2. A line along north-south.
3. A horizontal plane.
4. A vertical plane.

The torque on a bar magnet due to the earth's magnetic field is maximum when the axis of the magnet is

(a) Perpendicular to the field of the earth

(b) Parallel to the vertical component of the earth's field

(c) At an angle of 33o with respect to the N-S direction

(d) Along the North-South (N-S) direction

An electron changes its position from orbit n = 4 to the orbit n = 2  of an atom. The wavelength of the emitted radiation’s is (R = Rydberg’s constant)

(a)

(b)

(c)

(d)

Which of the following is not true for wire wound resistor?

A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.16 Tesla experiences a torque of magnitude 0.032 Joule. The magnetic moment of the bar magnet will be

(a) 0.23 Joule/Tesla

(b) 0.40 Joule/Tesla

(c) 0.80Joule/Tesla

(d) Zero