Animals: The label on a bottle of pet vitamins lists dosage guidelines.
What dosage would you give to each of these animals?
(a) a 18 kg adult dog
(b) a 6 kg cat
(c) a 18 kg pregnant dog

Answer carefully: (a) Two large conducting spheres carrying charges Q_(1) and Q_(2) are brought close to each other. Is the magnitude of electrostatic force between them exactly given by Q_(1) Q_(2)//4pi epsilon_(0) r_(2) , where r is the distance between their centers? (b) If Coulomb’s law involved 1//r^(3) dependence (instead of 1//r^(2) ), would Gauss’s law be still true ? (c) A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point? (d) What is the work done by the field of a nucleus in a complete circular orbit of the electron? What if the orbit is elliptical? (e) We know that electric field is discontinuous across the surface of a charged conductor. Is electric potential also discontinuous there? (f) What meaning would you give to the capacitance of a single conductor? (g) Guess a possible reason why water has a much greater dielectric constant (= 80) than say, mica (= 6).

A solid cube just gets completely immersed in water when a 0.2 kg mass is placed on it. If the mass is removed, the cube is 2 cm above the water level. What is the length of each side of the cube? (a) 6 cm (b) 8 cm (c) 10 cm (d) 12 cm

A housewife wishes to mix together two kinds of food, X and Y, in such a way that the mixture contains at least 10 units of vitamin A, 12 units of vitamin B and 8 units of vitamin C The vitamin contents of 1 kg of each food are given below min contents of 1 kg of each food are given below . If 1 kg of food X costs 6 and 1 kg of food Y costs 10, find the minimum cost of the mixture which will produce the diet.

In the following items, each passage consists of six sentences. The first and sixth sentence are given in the beginning as S_(1) and S_(6) . The middle four sentences in each have been jumbled up. These are labelled P, Q, R ans S. You are requested to find out the proper sequence of the four sentences and mark according on the Answer Sheet. S_(1): My friend had a dog. S_(6): He took it to the veterinary hospital. P: He was very much upset. Q: Two days late it returned home. R: Its right ear had been torn off. S: One day he could not find the dog any where. The proper sequence should be (a) R P S Q (b) P S Q R (c) S P Q R (d) S Q R P

A man of mass 70 kg stands on a weighing machine in a lift , which is moving (a) upwards with a unifrom speed of 10^(-1) (b) downwards with a unifrom acceleration of 5 ms^(-2) (c) upwards with a unifrom acceleration of ms^(-2) What would be th readings on the scale in each case ? (d) What would be the reading if the lift machanism failed and it hurtled down freely under gravity ?