Refraction through a Lens — Physics STD 10 — Question

A light ray suffers reflection and refraction at the boundary in passing from air to water. Draw a neat labelled ray diagram to show it.

How do bats avoid obstacles in their way, when in flight?

Draw a diagram to show the waveforms of a pure note and a musical note, of the same pitch and same loudness.

The resistance of filament of an electric heater is 500 Ω It is operated at 200V for 1 hour daily. Calculate the current drawn by the heater and the energy consumed in kWh, by the heater in a month of 30 days.

Find the effective resistance in the following circuit diagrams (Fig.):

Study the diagram below.



Complete the diagram to form the image of the object AB.

In given figure a ray of light PQ is incident normally on the face AB of an equilateral glass prism. Complete the ray diagram showing its emergence into air after passing through the prism.
(a) Write the angles of incidence at the faces AB and AC of the prism.
(b) name the phenomenon which the ray of light suffers at the face AB, AC and BC of the prism.

Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply of the energy supplied in kWh to the three heaters in 5 hours.

Ice cream appears coder to the mouth than water at 0℃. Give reason.