A radioactive source emits X–rays of very short wavelength (10 -13m ). what is the frequency of these rays?
The strength of an electromagnet increases with
Which of the following will increase the boiling point of water?
I. Taking it to a high altitude
II. Dissolving a salt into it
III. Heating it in a sealed flask
IV. Increasing the rate of heat supply
.
Transformers are designed so that energy losses are reduced to a minimum. This is achieved through which of these process?
I. Using a soft iron ore
II. Laminating the iron core to reduce energy loses due to eddy current
III. Designing an efficient iron core
