Fill in the blanks:
(i) Dolphins and bats hear_____.
(ii) If the energy in a longitudinal wave travels from south to north, the particles of the medium would be vibrating in____.

Fill in the blanks: (i) Water enters the root cell through a _____. (ii) Deoxygented blood from the cardiac muscles drains into the right atrium by the _____.

Fill in the blanks: (i) _____ and _____increases the surface area of cerebrum. (ii) Impulses travels rapidly in _____ neutrons.

Fill in the blanks: (i) Conductivity of water has resulted from the ____ of water. (ii) _____decomposition reaction may occur in the presence of heat or light.

Fill in the blanks: (i) The amount of work done to move charge from one point to another is called_____. (ii) When a circuit is open,_____ cannot pass through it.

Mark the correct choice as : (a) Both assertion and reason are true and reason is the correct explanation of assertion. (b) Both assertion and reason are true but reason is not the correct explanation of assertion. (c) Assertion is true but reason is false. (d) Assertion is false but reason is true. (e) Both Assertion and reason are false.Reason : Sound is mechanical wave, which require medium to travel. Assertion : We cannot hear the sound produced by a vibrating pendulum. Reason : The frequency of the pendulum is very less.

True or false. If false give the correct statement. (i) Sound can travel through solids, gases, liquids and even vacuum. (ii) The particles of the medium move from one part to another part during propagation.

Fill up the blanks in the following paragraph by selecting the correct option A. overset("i")("___") methods work on the principle of avoiding chances of ovum and sperms meeting B. overset("ii")("___") is one such method in which the couples avoid coitus from day 10 to 17 of the menstrual cycle C. overset("iii")("___") is another method in which the male partner withdraws his penis from the vagina just before ejaculation so as to avoid insemination D. overset("iv")("___") method is based on the fact that ovulation and therefore the cycle do not occur during the period of intense loctation following parturition.

Select the correct option to fill up the blanks. (i) Diseases which are easily transmitted from one person to another, are called ______ diseases. (ii) In human body, parasite of malaria initially multiplies within the ____ and then attack the ______. (iii) _____ is the yellowish fluid secreted by mother during the initial days of lactation. (iv) _____ and ____ are the primary lymphoid organs.

Write the relation for velocity of longitudinal waves in, (i) One dimensional rod (ii) Three dimensional rod (iii) Liquid medium