Types of Motion Std X Choose the correct answer 1. Which of the following represent the circular motion---------( d ) a. Ball sliding down an inclined plane b. motion of simple of pendulum b. A freely falling body d. A stone tied to a thread and whirled 2. The waves carries --------------( b ) a. Power b. energy c. displacement d. work 3. Which of the following is longitudinal wave---------------( d ) a. Radio wave b. X- rays c. light wave d. sound waves 4. The S.I unit of wave length is -----------------( c ) a. Cm b. dm c. m d. km 5. The wavelength of a wave is 4 m and two wave per second possess a point, Then the speed of the wave is ------------------ a. 2 m/s b. 8 m/s c. 6m/s d. 4 m/s Q II Complete the following sentences 1. Waves are produced by distrubances. 2. The speed of a wave depends on nature of the medium 3. The distance between two consecutive compressions / rarefaction wave length. 4. The type of wave to which electromagnetic wave belongs to transverse wave. 5. In a longitudinal wave the vibration of particles, and the direction of wave are same Q III Match the following A B 1. Longitudinal wave Oscillations in spring 2. Transverse wave Crests and tough 3. Simple harmonic motion Oscillation of a simple pendulum
Q IV Answer the following 1. Give differences between a transverse wave and a longitudinal wave Transverse wave Longitudinal wave The wave propogates in the The wave propogates in the form of crests and toughs form of compressions and Rarefaction 2. One crests and one trough one compression and one Constitute a wave rarefaction constitute a wave Q 2. Do the of the medium in which a wave moves travel along with the wave? Explain with an example. Ans The particles of the medium in which a wave moves, do not travel along with the wave. This can be shown by the following activity. Place a paper ball on the surface of water in the pond. Throw a small pebble to the still water. You will find the waves forming and these waves are transverse waves observe the paper ball it is moving up and down only, but it is not moving forward along with the waves. Only energy is carried. 3. If we double the frequency of a vibrating object, what happens to its time period? A.Time period and frequency are inversely proportional to each other. If we double the frequency of a vibrating object, then the time period of vibration reduces to half. 4 If the frequency of tranverse wave is 10hz and the distance between the two consecutive wave crests is 2m. Calculate the wave speed. A.If the frequency of a wave motion is f and the distance between the two consecutive wave crests λ, then the speed of the wave is denoted as v V=fλ given f = 10Hz
λ = 2m v = 10 X 2 = 20m/s 5 define simple harmonic motion and give two example of the same. A A particle is said to be in simple harmonic motion if the acceleration of the particle is always directed towards a fixed point called mean position and the magnitude of the acceleration is directly proportional to the displacement of the particle from mean position. Eg i) Oscillation of a simple pendulum. ii) When a tuning fork is hit against rubber pad, its prongs execute Simple Harmonic Motion. 6 Give two practical applications of Simple Harmonic Motion. A 1. Simple Harmonic Motion of a pendulum used for calculating time in clocks 2. Tuning the musical instrument is done with the vibrating tuning fork which executes simple harmonic motion.
Std VII Cellular Organization Q I Choose the correct answer 1. Microscope was invented by Leeuwenhoek. a. Leeuwenhoek b. Parashara c. Robert Hook d. Robert Brown 2. Cell was discovered by Robert Hook a. Leeuwenhoek b. Parashara c. Robert Hook d. Robert Brown 3. A true nucleus is present in eukaryotic cell a. Prokaryotic cell b. bacteria cell c. virus d. eukaryotic cell 4. The power house of a cell is mitochondrion a..nucleus b. ribosome c. mitochondrion d. lysosome 5. A group of cells with similar structure and function is a tissue a. tissue b. organ c. organ system d. organism Q II Fill in the blanks 1. The combination of different organs which out a particular function is a system 2. Ribosome helps in protein synthesis. 3. Lysosome helps in the digestion of organic substance. 4. Paramecium is an example for unicellular organism 5. The part which controls and co-ordinate all the activities of the cell is nucleus 6. In a prokaryote, genetic material is represented by chromatin Q III Answer the following 1. Define a cell. Explain the structure of a typical cell Ans. A cell is the structural and functional unit of an organism. The cell has a and organelles like mitochondria, endoplasmic reticulum, and golgi complex. 2. Draw a neat diagram of eukaryotic cell and label its parts.
Ans Refer page No. 18 fig. 2.2 3. Difference between an organ and a tissue Organ It is a combination of different types of tissues which performs a specific function. Tissue A tissue is a group of cells with similar structure and function. 4. Mention the functions of the parts of a eukaryotic cell. Ans Nucleus Controls and co-ordinates all the activities of the cell. Mitochondrion Helps in producing energy from food. Ribosome Helps in protein synthesis. Centriole Helps in cell division. Vacuole Stores wastes, secretions and reserve food products in the cell. Endoplasmic reticulum It transports substances from one part of the cell to the other and from one cell to another. Golgi complex It helps in the secretion of chemicals required for cellular activities. Lysosome Helps in the digestion of organic substances present in the cell. It destroys its own cell when cell become old or damaged. 5. Distinguish between the following pairs Ans Prokaryotic cells Eukaryotic cells 1. The cytoplasm shows The cytoplasm shows small ribosome large ribosome. 2. Genetic material is Genetic material is present in the represented by form of chromatin. DNA
b) Unicellular organisms Multicellular organisms Organisms with a singke cell are called unicellular organisms. Eg. Banyan tree, elephant etc. organisms with many cells are multicellular organisms. eg. Amoeba, euglena etc 6. Draw a neat labelled diagram of a prokaryotic cell. Ans Refer page No 17 Fig. 2.1 7. Describe the structure of a prokaryotic cell. Ans The cell is surround by cell membrane and a cell wall. The genetic material is represented by nacked Deoxy Ribo Nucleic Acid. The cytoplasm shows small ribosome. A cell with this pattern of organization is called a prokaryotic cell. 8. Name the four levels of our body organization in organisms Ans The four levels of our body organization in organisms are Cell. Tissue, Organ, and System. 9. n the advantage of tissue-organ level of body organization. Ans. The advantages of tissue organ level of body organization is that cell differentiate into true tissues and organs for specific functions.