Home
Class 12
PHYSICS
A student measures the thickness of a hu...

A student measures the thickness of a human hair by looking at it through a microscope of magnification 100. He makes 20 observations and finds that the average width of the hair in the field of view of the microscope is 3.5mm. What is the estimate on the thickness of hair?

A

0.5 cm

B

0.035 cm

C

`0.035 cm`

D

`3.5 cm`

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • APPENDICES (REVISION EXERCISE)

    AAKASH SERIES|Exercise MOTION IN A STRAIGHT LINE|59 Videos
  • APPENDICES (REVISION EXERCISE)

    AAKASH SERIES|Exercise MOTION IN A PLANE|87 Videos
  • APPENDICES ( REVISION EXERCISE )

    AAKASH SERIES|Exercise REVISION EXERCISE (MAGNETISM AND MATTER )|52 Videos
  • ATOMS

    AAKASH SERIES|Exercise PRACTICE EXERCISE|21 Videos

Similar Questions

Explore conceptually related problems

A student measures the thickness of a human hair using a microscope of magnification 100. He makes 20 observations and find that the average thickness (as viewed in the microscope) is 3.5 mm. What is the estimate of the thickness of hair?

In a YDSE a parallel beam of light of wavelength 6000Å is incident on slits at angle of incidence 30^(@) . A and B are two thin transparent films each of refractive index 1.5. thickness of A is 20.4mum . Light coming through A and B have intensities I and 4I resepctively on the screen. Intensity at point O which is symmetric relative to the slits is 3I. The central maxima is above O. (i). what is the maximum thickness of B to do so. Assuming thickness of B to be that found in part (i) Answer the following parts. (ii). Find fringe width, maximum intensity and minimum intensity on screen. (iii). Distance of nearest minima from O (iv) intensity at 5 cm on either side of O.

For his 18th birthday in February Peter plants to turn a hut in the garden of his parents into a swimming pool with an artifical beach. In order to estimate the consts for heating the water and the house , peter obtains the data for the natural gas combustion and its price. What is the total energy (in MJ) needed for Peter's "winter swimming pool" calculated in 1.3 and 1.4? How much natural gas will he need, if the gas heater has an efficiency of 90.0% ? What are the different costs for the use of either natural gas or electricity ? Use the values given by PUC for your calculations and assume 100% efficiency for the electric heater. Table 1: Composition of natural gas {:("Chemical substance","mol fraction x",D_(1)H^(@)(KJ mol^(-1))^(-1),S^(@)(J mol^(-1)K^(-1))^(-1),C_(p)^(@)(J mol^(-1)K^(-1))^(-1)),(CO_(2(g)),0.0024,-393.5,213.6,37.1),(N_(2(g)) ,0.0134,0.0,191.6,29.1),(CH_(2(g)),0.9732,-74.6,186.3,35.7),(C_(2)H_(3 (g)),0.0110,-84.0,229.2,52.2),(H_(2)O_(g),-,-285.8,70.0,75.3),(H_(2)O_(g),-,-241.8,188.8,33.6),(H_(2)O_(g),-,0.0,205.2,29.4):} Equation J=E(A.Deltat)^(-1) =!! lambda "wall" . DeltaT. d^(-1) , where J= energy flow E along a temperature gradient (wall direction Z) par area A and time Deltat , d-wall thickness , lambda wall -heat conductivity , DeltaT - difference in temperature between the inside and the outside of the house.

AAKASH SERIES-APPENDICES (REVISION EXERCISE)-LAW OF MOTION
  1. A student measures the thickness of a human hair by looking at it thro...

    Text Solution

    |

  2. A body of mass 1 kg is moving with velocity 30 ms^(-1) due north. It i...

    Text Solution

    |

  3. A force of 20 N acts on a body of mass 5kg at rest. What is the accele...

    Text Solution

    |

  4. A truck starts from rest and accelerates uniformly at 2.0 ms^(-2) . At...

    Text Solution

    |

  5. A particle of mass 70 g, moving at 50 cm/s , is acted upon by a variab...

    Text Solution

    |

  6. A ball of mass 400 gm is dropped from a height of 5m. A boy on the gro...

    Text Solution

    |

  7. A batsman deflects a ball by an angle of 60° without changing its init...

    Text Solution

    |

  8. A body of mass 5 kg is at rest. Three force F(1) = 10 N due North F2=1...

    Text Solution

    |

  9. The momentum of a body in two perpendicular direction at any time 't' ...

    Text Solution

    |

  10. A bullet is fired from a gun. The force on the bullet is given by F=60...

    Text Solution

    |

  11. A body of mass 5kg starts from the origin with an initial velocity of...

    Text Solution

    |

  12. A 15Kg mass is accelerated from rest with a force of 100N. As it moves...

    Text Solution

    |

  13. A cart loaded with sand moves along a horizontal floor due to a consta...

    Text Solution

    |

  14. Two billiard balls each of mass 0.05 kg moving in opposite direction w...

    Text Solution

    |

  15. Figure 5.17 shows the position-time graph of a body of mass 0.04 kg . ...

    Text Solution

    |

  16. The driver of a three-wheeler moving with a speed of 36 km/h sees a ch...

    Text Solution

    |

  17. If the average velocity of a body moving with uniform acceleration und...

    Text Solution

    |

  18. Five persons A, B, C, D & E are pulling a cart of mass 100kg on a smoo...

    Text Solution

    |

  19. A box is put on a scale which is adjusted to read zero, when the box i...

    Text Solution

    |

  20. Two masses each equal to m are lying on x-axis at (-a,0)(+a,0) respect...

    Text Solution

    |

  21. Water is flowing at a speed of 1.5ms^(-1) through a horizontal tube of...

    Text Solution

    |