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

Give one example of a class I lever where mechanical advantage is more than one ?

A ray of green light enters a liquid from air, as shown in Fig. The angle 1 is 45° and angle 2 is 30°. 

1. Find the refractive index of the liquid.
2. Show in the diagram the path of the ray after it strikes the mirror and re-enters in air. Mark in the diagram the angles where ever necessary.
3. Redraw the diagram if plane mirror becomes normal to the refracted ray inside the liquid. State the principal used. 

Draw a diagram of a lever which is always used as a force multiplier. How is the effort arm related to the load arm in such a lever?

An electric heater of power 3 kW is used for 10 h. How much energy does it consume? Express your answer in

1. kWh,
2. joule.

shows a nut cracker name the class of lever ?

State two applications of echo.

Explain how the speed of sound can be determined by the method of echo.

State Ohm’s law and draw a neat labelled circuit diagram containing a battery, a key, a voltmeter, an ammeter, a rheostat and an unknown resistance to verify it. 

What is the necessary condition for a conductor to obey Ohm’s law? 

1. Draw a V-I graph for a conductor obeying Ohm’s law.
2. What does the slope of V–I graph  for a conductor represent?

What is an ohmic resistor? Give one example of an ohmic resistor. Draw a graph to show its current voltage relationship. How is the resistance of the resistor determined from this graph?

The lever for which the mechanical advantage is less than 1 has :

Class II levers are designed to have ______.

A 4 m long rod of negligible weight is to be balanced about a point 125 cm from one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm.

1. If a weight W is placed at a distance of 250 cm from the support on the longer arm to balance the rod, find W.
2. If a weight 5 kgf is kept to balance the rod, find its position.
3. To which class of lever does it belong?

A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand.

1. Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions.
2. State the kind of lever.
3. Calculate:
   1. load arm,
   2. effort arm,
   3. mechanical advantage and
   4. the effort needed.

Fig 3.17 below shows a lever in use.

(a) To which class of lever does it belong?
(b) If FA = 80 cm, AB = 20 cm, find its mechanical advantage.
(c) Calculate the value of E.

Which of the following is an ohmic resistance?

In a conductor 6.25 × `10^16` electrons flow from its end A to B in 2 s. Find the current flowing through the conductor (e = 1.6 × `10^-19` C)

An electric bulb draws 1.2 A current at 6.0 V. Find the resistance of filament of bulb while glowing.

A car bulb connected to a 12 volt battery draws 2 A current when glowing. What is the resistance of the filament of the bulb? Will the resistance be more same or less when the bulb is not glowing?