English Medium Class 9 - CBSE Question Bank Solutions for Science

On the basis of Rutherford’s model of an atom, which subatomic particle is present in the nucleus of an atom?

Identify the Mg2+ ion from the Fig. where, n and p represent the number of neutrons and protons respectively

Calculate the number of neutrons present in the nucleus of an element X which is represented as `""_15^31"X"`

Choose the wrong statement

______ and ______ are both conducting tissues.

Find out incorrect sentence

Write true (T) or false (F)

Anabaena belongs to the kingdom Monera.

Four cars A, B, C, and D are moving on a levelled road. Their distance versus time graphs are shown in Fig. 8.2. Choose the correct statement.

Two substances, A and B were made to react to form a third substance, A2B according to the following reaction

\[\ce{2A + B -> A2 B}\]

Which of the following statements concerning this reaction are incorrect?

(i) The product A2B shows the properties of substances A and B

(ii) The product will always have a fixed composition

(iii) The product so formed cannot be classified as a compound

(iv) The product so formed is an element

Slope of a velocity-time graph gives

In which of the following cases of motions, the distance moved and the magnitude of displacement are equal?

The displacement of a moving object in a given interval of time is zero. Would the distance travelled by the object also be zero? Justify your answer.

A car starts from rest and moves along the x-axis with constant acceleration 5 ms^–2 for 8 seconds. If it then continues with constant velocity, what distance will the car cover in 12 seconds since it started from the rest?

An object is dropped from rest at a height of 150 m and simultaneously another object is dropped from rest at a height of 100 m. What is the difference in their heights after 2s if both the objects drop with the same accelerations? How does the difference in heights vary with time?

Using the following data, draw time - displacement graph for a moving object:

Use this graph to find average velocity for the first 4 s, for the next 4 s and for the last 6 s.

Obtain a relation for the distance travelled by an object moving with uniform acceleration in the interval between 4th and 5th seconds.

An object is put one by one in three liquids having different densities. The object floats with `1/9, 2/11` and `3/7` parts of their volumes outside the liquid surface in liquids of densities d₁, d₂ and d₃ respectively. Which of the following statement is correct?

Establish the relationship between the speed of sound, its wavelength and frequency. If the velocity of sound in air is 340 m s^–1, calculate

(i) wavelength when the frequency is 256 Hz.

(ii) frequency when the wavelength is 0.85 m

Discuss various methods for weed control.

Take an earthen pot (mutka), some pebbles and sand. Design a small-scale filtration plant that you could use to clean muddy water.