(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

If the lens is of focal length 25 cm. Calculate the power of the lens.

If there is a convex lens of focal length 75 cm and a concave lens of focal length 40 cm, then calculate their combined power and combined focal length.

Why does it become pleasantly warm when the lakes start freezing?

The lens of power + 1·0 D is ______.

The melting point of napthalene is 80°C and the room temperature is 25°. A sample of liquid napthalene at 90° is cooled down to room temperature. Draw a temperature-time graph to represent this cooling. On the graph mark the region which corresponds to the freezing process.

Give one example of a radio isotope.

State one use of radio isotopes.

In what unit is the power of a lens expressed?

The V-I graph for a series combination and for a parallel combination of two resistors is shown in the figure below. Which of the two A or B. represents the parallel combination? Give reasons for your answer.

Find the equivalent resistance between points A and B.

Find the equivalent resistance between points A and B

Two resistors of 4Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
(i) Draw a labelled circuit diagram showing the above arrangement.
(ii) Calculate the current in each resistor. What is an Ohmic resistor?

(i) Two sets A and B, of three bulbs each, are glowing in two separate rooms. When one of the bulbs in set A is fused, the other two bulbs also cease to glow. But in set B, when one bulb fuses, the other two bulbs continue to glow. Explain why this phenomenon occurs.

(ii) Why do we prefer arrangements of Set B for house circuiting?

Find the equivalent resistance between A and B

The speed of light in air is 3 × 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5

Draw a V-I graph for a conductor at two different temperatures. What conclusion do you draw from your graph for the variation of resistance of conductor with temperature?

State the order of resistivity of (i) a metal, (ii) a semiconductor and (iii) an insulator. 

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

State how are the two resistors joined with a battery when equivalent resistance is more than either of the two resistances. 

State how are the two resistors joined with a battery when same current flows in each resistor.