Solutions of NCERT Class XI Physics Chapter 2 Units and Dimensions

A calorie is a unit of heat (energy in transit) and it equals about 4.2 J where 1J = 1 kg m2 s-2. Suppose we employ a system of units in which the u . . .

A new unit of length is chosen such that the speed of light in vacuum is unity. What is the distance between the Sun and the Earth in terms of the n . . .

Which of the following is the most precise device for measuring length : (a) a vernier callipers with 20 divisions on the sliding scale (b) a screw . . .

The mean diameter of a thin brass rod is to be measured by vernier callipers. Why is a set of 100 measurements of the diameter expected to yield a m . . .

The photograph of a house occupies an area of 1.75 cm2 on a 35 mm slide. The slide is projected on to a screen, and the area of the house on the scr . . .

State the number of significant figures in the following : (a) 0.007 m2 (b) 2.64 × 1024 kg (c) 0.2370 g cm-3 (d) 6.320 J (e) 6.032 N m-2 (f) 0. . . .

The length, breadth and thickness of a rectangular sheet of metal are 4.234 m, 1.005 m, and 2.01 cm respectively. Give the area and volume of the sh . . .

The mass of a box measured by a grocer's balance is 2.30 kg. Two gold pieces of masses 20.15 g and 20.17 g are added to the box. What is (a) the . . .

A physical quantity P is related to four observables a, b, c and d as follows : P= a^3b^2/√c d The percentage errors of measurement in a, b, c and d . . .

A book with many printing errors contains four different formulas for the displacement y of a particle undergoing a certain periodic motion (a) y = . . .

A famous relation in physics relates 'moving mass' m to the 'rest mass' mo of a particle in terms of its speed v and the speed of li . . .

One mole of an ideal gas at standard temperature and pressure occupies 22.4 L (molar volume). What is the ratio of molar volume to the atomic volume . . .

Explain this common observation clearly : If you look out of the window of a fast moving train, the nearby trees, houses etc. seem to move rapidly i . . .

A parsec is a convenient unit of length on the astronomical scale. It is the distance of an object that will show a parallax of 1" (second of a . . .

The nearest star to our solar system is 4.29 light years away. How much is this distance in terms of parsecs? How much parallax would this star (nam . . .

The Sun is a hot plasma (ionized matter) with its inner core at a temperature exceeding 10^7 K, and its outer surface at a temperature of about 6000 . . .

When the planet Jupiter is at a distance of 824.7 million kilometers from the Earth, its angular diameter is measured to be 35.72" of arc. Calc . . .

A man walking briskly in rain with speed v must slant his umbrella forward making an angle θ with the vertical. A student derives the following rela . . .

It is claimed that two caesium clocks, if allowed to run for 100 years, free from any disturbance, may differ by only about 0.02 s. What does this i . . .

Estimate the average mass density of a sodium atom assuming its size to be about 2.5 Å. (Use the known values of Avogadro's number and the . . .

The unit of length convenient on the nuclear scale is a fermi : 1 f = 10^-15 m. Nuclear sizes obey roughly the following empirical relation : r = r0 . . .

A LASER is a source of very intense, monochromatic, and unidirectional beam of light. These properties of a laser light can be exploited to measure . . .

A SONAR (sound navigation and ranging) uses ultrasonic waves to detect and locate objects under water. In a submarine equipped with a SONAR, the tim . . .

It is a well known fact that during a total solar eclipse the disk of the moon almost completely covers the disk of the Sun. From this fact and from . . .

These are some of the difficult questions in Chapter 3 of Class XI Physics NCERT - Motion in a Plane. I was able to provide only video solutions.

The photograph of a house occupies an area of 1.75 cm2 on a 35 mm slide. The slide is projected on to a screen, and the area of the house on the scr . . .