List of top Questions asked in CBSE Class X

Distinguish between overloading and short-circuiting of a circuit.
How will you identify live wire and neutral wire in a domestic electric circuit?
Write any two differences between direct current and alternating current.
List any two features of the electric current used in the houses of India.
When the path of a light ray refracted through a glass prism is reversed, how will the angle of deviation change? Explain.
Draw the ray diagram for refraction of light through a glass prism and mark angle of refraction and angle of deviation.
An object is placed at a distance of 30 cm in front of a convex lens of focal length 15 cm. Use lens formula to determine the position of the image. What will be the size of the image in this case?
How to connect three resistors each of resistance 8 $\Omega$, so that the equivalent resistance of the combination is 12 $\Omega$? Draw diagram of the combination and justify your answer.
Draw a ray diagram to show the correction of eye defect of an old man who cannot see an object placed closer than 1 m from his eye clearly.
State the range of the power of accommodation of a normal human eye.
How does the change in curvature of the eye lens help us in the process of seeing the nearby objects clearly?
Arrange the given material mediums in increasing order of speed of light through them. Given Refractive Indices:
  • A = 1.50
  • B = 1.46
  • C = 1.31
  • D = 1.77
Define absolute refractive index of an optical medium.
Rays from the sun converge at a point 25 cm behind a convex lens. The distance at which an object be placed in front of the lens to get a virtual image, is:
To restore clear vision in persons whose size of the eyeball has reduced, he/she is suggested to use suitable
Show the formation of ionic compound CaO with electron dot structure.
Give reasons for the following: The wires carrying current in homes have a coating of PVC.
Carbon cannot reduce the oxides of Na or Mg.
Carbon cannot reduce the oxides of Na or Mg.
Solder, an alloy of lead and tin, is used for welding electrical wires.
Give reasons for the following: Ionic compounds have generally high melting points and boiling points.
Give reasons for the following: Ionic compounds have generally high melting points and boiling points.
What happens when ethanol is heated with excess concentrated sulphuric acid at 443 K? Write chemical equation involved. What is the role of concentrated sulphuric acid in this reaction?
Write the chemical equation of reaction of ethanol with ethanoic acid in the presence of concentrated H$_2$SO$_4$. Write the name of this reaction.
Write structural formula and name of 4$^{th}$ member of alcohol homologous series.