Answer: 2 cm
Explanation:
Given , for a converging lens
Focal length : 
Height of object : 
Object distabce from lens : 
Using lens formula:
, we get
, where v = image distance from the lens.
On solving aboive equation , we get

Formula of Magnification :
, where h' is the height of image.
Put value of u, v and h in it , we get

Hence, the height of the image is 2 cm.
Answer:
the correct one is D,
Ultraviolet, x-ray, gamma ray
Explanation:
Electromagnetism radiation are waves of energy that is expressed by the Planck relationship
E = h f
where h is the plank constant and f the frequency of the radiation.
Also the speed of light is
c = λ f
we substitute
E = h c /λ
therefore to damage the cells of the body radiation of appreciable energy is needed
microwave radiation has an energy of 10⁻⁵ eV
infrared radiation E = 10⁻² eV
visible radiation E = 1 to 3 eV
radiation Uv E = 3 to 6 eV
X-ray E = 10 eV
gamma rays E = 10 5 eV
therefore we see that the high energy radiation is gamma rays, x-rays and ultraviolet light.
When checking the answers, the correct one is D
Answer:
B. An Iron Bar place in a room becomes cooler than its surroundings.