CBSE Pathshala

Question :1     A proton enters in a straight line in a uniform magnetic field along the field direction. How will its path and velocity change? Answer:    As the proton is moving along the field direction, thus no force acts on it and the velocity and the path will not change. It will keep on moving with the same speed along the field direction. Question :2     A positive charge is moving vertically upwards in magnetic field towards south. In which direction will it be deflected? Answer:    If positive charge is moving upwards the corresponding current is also upwards, the magnetic field is towards south. Using Fleming’s left hand rule force is towards east and deflection towards east. Question :3     Free electrons always keep on moving in the conductor. Even then no magnetic force acts on them in a magnetic field. Why? Answer:    In the absence of external potential di...

1.State the  reason  of  introducing  Italian  bee  variety  in  bee  farms. 1 2 . State one demerit with composite fish culture system. 1 3. State one importance of photo period in agriculture.   1 4. Name one micronutrient and one macronutrient which plants take from   the soil . 1 6.What  is meant by  the term   green  manure  ?   State its role in agriculture. 2 7.State two  functions  of Vacuoles  in   a  plant  cell . 2 8.List two  characteristics  of  cork  cells which  help  them  to  function as  protective  tissue ? 2 9. What  is  composite  fish  culture  system  ?    State  one   merit     and  one    demerit  of  such  a system 2 10. Name the energy cu...

1. Name the respiratory organs of (a) Fish (b) Mosquito (c) Earthworm (d) Dogs             Answer: (1) gills    (2) Trachea     (3) Skin    (4) lungs 2. Although bile juice has no digestive enzyme. It is still considered to be very important for digestion of food .Give two reasons. Answer: (1) Bile juice helps in to emulsify fat. (2) Due to basic nature it neutralizes the acidic traces reaching the small intestine. 3. What is osmoregulation? How does it takes place in human beings ?   Answer: Balance the water & salt level in body is called osmoregulation. It takes place nephron by the ADH (anti diuretic hormone). It effects the permeability of cells of nephron for absorption of water. 4. Define phototropism. Which hormone is responsible for it . How? Answer:  The growth movement of plants induced by sti...