Refraction through a Lens — Physics STD 10 — Question

Name a substance of which the resistance remains almost unchanged by the increase in temperature.

How does the power of a lens change is its focal length is doubled?

what conclusion do you draw about the nature of white light in part (b)?

Give one use of electromagnetic radiations in Infrared radiation.

Why does a spanner have a long handle?

What material is used for making wire to prepare heating coils? Give a reason.

An object is placed in front of a convex lens such that the image formed has the same size as that of the object. Draw a ray diagram to illustrate this.

Name the scientist who discovered Infra-red waves

State expression for Cells connected in parallel.

Name the quality which is measured in kW.