A fuse is rated 8A. Can it be used with an electrical appliance rated 5 KW, 200 V? Give a reason.

September 21, 2021

  1. A fuse is rated 8A. Can it be used with an electrical appliance rated 5 KW, 200 V? Give a reason.
  2. Name two safety devices which are connected to the live wire of a household electric circuit.

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A person is standing at the sea shore. An observer on the ship which is anchored in between a vertical cliff and the person on the shore fires a gun

September 20, 2021

A person is standing at the sea shore. An observer on the ship which is anchored in between a vertical cliff and the person on the shore fires a gun. The person on the shore hears two sounds, 2 seconds and 3 seconds after seeing the smoke of the fired gun. If the speed of sound in the air is 320 ms-1 then calculate:

  1. the distance between the observer on the ship and the person on the shore.
  2. the distance between the cliff and the observer on the ship.

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The diagram above shows a wire stretched over a sonometer

September 19, 2021

The diagram above shows a wire stretched over a sonometer. Stems of two vibrating tuning forks A and B are touched to the wooden box of the sonometer. It is observed that the paper rider (a small piece of paper folded at the centre) present on the wire flies off when the stem of vibrating tuning fork B is touched to the wooden box but the paper just vibrates when the stem of vibrating tuning fork A is touched to the wooden box.

  1. Name the phenomenon when the paper rider just vibrates.
  2. Name the phenomenon when the paper rider flies off.
  3. Why does the paper rider fly off when the stem of tuning fork B is touched to the box?

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Draw the diagram of a right angled isosceles prism which is used to make an inverted image erect

September 18, 2021

Draw the diagram of a right angled isosceles prism which is used to make an inverted image erect.

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An object is placed at a distance of 12 cm from a convex lens of focal length 8 cm

September 17, 2021

An object is placed at a distance of 12 cm from a convex lens of focal length 8 cm. Find:

  1. the position of the image
  2. nature of the image

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An object AB is placed between O and F1 on the principal axis of a converging lens as shown in the diagram

September 16, 2021

An object AB is placed between O and F1 on the principal axis of a converging lens as shown in the diagram.

Copy the diagram and by using three standard rays starting from point A, obtain an image of the object AB.

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A ray of light XY passes through a right angled isosceles prism as shown below

September 15, 2021

A ray of light XY passes through a right angled isosceles prism as shown below.

  1. What is the angle through which the incident ray deviates and emerges out of the prism?
  2. Name the instrument where this action of prism is put into use.
  3. Which prism surface will behave as a mirror?

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Draw a diagram to show a block and tackle pulley system having a velocity ratio of 3 marking the direction of load(L), effort(E) and tension(T)

September 14, 2021

  1. Draw a diagram to show a block and tackle pulley system having a velocity ratio of 3 marking the direction of load(L), effort(E) and tension(T).
  2. The pulley system drawn lifts a load of 150 N when an effort of 60 N is applied. Find its mechanical advantage.
  3. Is the above pulley system an ideal machine or not?

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A half metre rod is pivoted at the centre with two weights of 20 gf and 12 gf suspended at a perpendicular distance

September 13, 2021

A half metre rod is pivoted at the centre with two weights of 20 gf and 12 gf suspended at a perpendicular distance of 6 cm and 10 cm from the pivot respectively as shown below.

  1. Which of the two forces acting on the rigid rod causes clockwise moment?
  2. Is the rod in equilibrium?
  3. The direction of 20 kgf force is reversed. What is the magnitude of the resultant moment of the forces on the rod?

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Derive a relationship between S.I. and C.G.S. unit of work

September 12, 2021

  1. Derive a relationship between S.I. and C.G.S. unit of work.
  2. A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of force. What should be the value of θ to get the maximum positive work?

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State any two advantages of electromagnets over permanent magnets

September 11, 2021

State any two advantages of electromagnets over permanent magnets.

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What are isobars

September 10, 2021

  1. What are isobars?
  2. Give one example of isobars.

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