Question

6. Permanent magnets are made of
a) hard magnetic materials
c) semiconductors
b)soft magnetic materials
d)superconductors
7. Interference of light signifies
a) wave nature of light
b) particle nature of light
c) dual nature of light
d) all of the above
8. For an electron accelerated through 10kV potential difference, the de Brogli
wavelength is
(a) 1.226nm
(b) 0.01226nm
(c) 122.6nm
(d) 0.126nm
9. The phase velocity is
(a) greater than group velocity (b) greater than particle velocity
c) greater than velocity of light
d)all of the above ​

Answer 1

6. c) semiconductors

7. c) dual nature of light

8. (b) 0.01226nm

Answer 2

Answer:

c semiconductor

c. dual nature of light

b. greater than particle velocity