Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

Rest mass energy of an electron is 0.54 MeV. If velocity of the electron is 0.8 c, then K.E. of the electron is (a) 0.36 MeV(b) 0.41 MeV(c) 0.48 MeV(d) 1.32 MeV

Amount of light entering into the camera depends upon(a) Focal length of the objective lens(b) Product of focal length and diameter of the objective lens(c) Distance of the object from camera(d) Aperture setting of the camera

The net resistance of a voltmeter should be large to ensure that:

In a step up transformer, 220 V is converted into 200 V. The number of turns in primary coil is 600. What is the number of turns in the secondary coil(a) 60(b) 600(c) 6000  (d) 100

In an electric circuit containing a battery, the charge (assumed positive) inside the battery:

In the experiment of diffraction at a single slit, if the slit width is decreased, the width of the central maximum(a) Increases in both Fresnel and Fraunhofer diffraction(b) Decreases both in Fresnal and Fraunhofer diffraction (c) Increases in Fresnel diffraction but decreases in Fraunhofer diffraction(d) Decreases in Fresnel diffraction but increases is Fraunofer diffraction.