Q1.Two charged spheres of radii 10 cm and 15 cm are connected by a thin wire. Current will flow through them if they have the same
1. charge on each
3. potential Which of the statements given above is/are correct?
(a) Only 1
(b) Only 2
(c) Only 3
(d) Both 1 and 2 Q2. In our houses we get 200 VAC What does the value 220 V represent?
(a) Constant voltage
(b) Effective voltage
(c) Average voltage
(d) Peak voltage Q3. Non-conductors, whose polarization is caused by an electric field, are known as
(d) Resistive conductorsQ4. Two pieces of metallic wire having equal lengths and equal volume placed in air have different resistances. The two wires must
(a) have different cross-sections
(b) have different temperatures
(c) be of different materials
(d) be of same densityQ5. Two similarly charged bodies are kept 5 cm apart in air. If the second body is shifted away from the first by another 5 cm, their force of repulsion will be
(d) reduced to one-fourthQ6. Ohm’s law defines
(a) a resistance
(b) current only
(c) voltage only
(d) both current and voltageQ7. 9. Which of the following nuclei undergo fission when struck by thermal neutrons?
Select the correct answer using the code given below:
(a) 1 and 2
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3 Q8. Internet communication uses optical fibre cables because of
(a) low cost
(b) free from virus threat
(c) high data carrying capacity
(d) faster than light communication of signalsQ9. Which one of the following metals occurs in nature in free state?
(d) Copper Q10. Analysis shows that a binary compound of X (atomic mass = 10) and Y (atomic mass = 20) contains 50% X. What is the formula of the compound?
(d) X2Y3Q11. Consider the following equation for the formation of ammonia from nitrogen and hydrogen: N2 + 3H2 = 2NH3 How many hydrogen molecules are required to react with 100 molecules of nitrogen?
(d) 400Q12. Which of the following pairs is/are correctly matched?
1. Isotopes: Atoms with same atomic number but different atomic mass
2. Isobars: Atoms with same number of neutrons but different atomic number
3. Isotones: Atoms with same mass number but different atomic number Select the correct answer using the code given below:
(a) 1, 2 and 3
(b) 1 only
(c) 1 and 2 only
(d) 2 only
1. 2. (b)3. (c)4. (c)5. (d)6. (a)7. (c)8. (c)9. (a)10. (c)11. (c)12. (b)