Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

What is the stopping potential when the metal with work function 0.6 eV is illuminated with the light of 2 eV

(a) 2.6 V

(b) 3.6 V

(c) 0.8 V

(d) 1.4 V

The amount of force exerted on a unit positive charge in an electric field is known as _____?

A capacitor is kept connected to the battery and a dielectric slab is inserted between the plates. During this process

(a) No work is done

(b) Work is done at the cost of the energy already stored in the capacitor before the slab is inserted

(c) Work is done at the cost of the battery

(d) Work is done at the cost of both the capacitor and the battery

A circular loop carrying a current is replaced by an equivalent magnetic dipole. A point on the axis of the loop is in:

A convex lens has 9 cm focal length and a concave lens has – 18 cm focal length.  The focal length of the combination in contact will be

(a) 9 cm

(b) – 18 cm

(c) – 9 cm

(d) 18 cm

A sodium atom is in one of the states labeled 'Lowest excited levels'. It remains in that state for an average time of 10^–8 sec, before it makes a transition back to a ground state. What is the uncertainty in energy of that excited state

(a) 6.56  × 10–8 eV

(b) 2 × 10–8 eV

(c) 10–8 eV

(d) 8 × 10–8 eV

When the angle of incidence on a material is 60°, the reflected light is completely polarized. The velocity of the refracted ray inside the material is (in ms^–1)

(a) 3

(b)

(c)

(d) 0.5

The potential difference between points  A and  B of adjoining figure is

(a)

(b)

(c)

(d) 2 V