Model Paper 1 — Physics STD 12 Science — Question

The path executed by a charged particle whose motion is perpendicular to magnetic field i

(a) A straight line

(b) An ellipse

(c) A circle

(d) A helix

A cathode emits 1.8  electrons per second, when heated. When 400V is applied to anode all the emitted electrons reach the anode. The charge on electron is 1.6 . The maximum anode current is

(a) 2.7 μA

(b) 29 μA

(c) 72 μA

(d) 29 μA

X-rays when incident on a meta

(a) Exert a force on it	(b) Transfer energy to it
(c) Transfer pressure to it	(d) All of the above

X-ray incident on a material:

1. Exerts a force on it.
2. Transfers energy to it.
3. Transfers momentum to it.
4. Transfers impulse to it.

The refractive index of a piece of transparent quartz is the greatest for

(a) Red light

(b) Violet light

(c) Green light

(d) Yellow light

In the following circuit, the resultant capacitance between A  and  B is 1mF. Then value of  C is

(a)  μF

(b)  μF

(c)  μF

(d)  μF

For the propagation of light wave, medium is required. This is according to:

The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100 W and 200 V lamp when not in use

(a) 400 Ω

(b) 200 Ω

(c) 40 Ω

(d) 20 Ω

For distance far away from centre of dipole the change in magnitude of electric field with change in distance from the centre of dipole is:

Dielectric constant is the: