Q1. To draw maximum current from a combination of cells, how should the cells be grouped?
(a) Series
(b) Parallel
(c) Mixed
(d) Depends upon the relative values of external and internal resistance
Q2. Rectifiers are used to convert
(a) DC to AC
(b) AC to DC
(c) Low voltage to high voltage
(d) None of these
Q3. A capacitor (condenser) is used in an electrical circuit in order to
(a) Prevent the flow of electric charge
(b) Store electric charge
(c) Produce electric charge
(d) Switch off the current
Q4. A fuse wire is used to
(a) Make the electrical circuit strong
(b) Convert AC into DC
(c) Covert DC into AC
(d) Prevent an unduly high electric current from passing through a circuit
Q5. Superconductors are the substance which
(a) Conduct electricity at low temp.
(b) Conduct electricity at high temp.
(c) Offer no resistance to the flow of electricity
(d) None of these
Q6. In a fusion reaction,
(a) The nucleus splits up into two fragments and energy is released
(b) Four hydrogen nuclei unit to form one helium nucleus and energy is absorbed
(c) Four hydrogen nuclei unit to form one helium nucleus and energy is released
(d) The nucleus splits up into tow fragments and energy is absorbed
Q7. The velocity of neutron in a nuclear reactor is retarded by
(a) Ordinary water
(b) Heavy water
(c) Mercury
(d) Alcohol
Q8. A radioactive element emits an alpha particle. The mass number of the element, after emission
(a) Remains unchanged
(b) Increases by one
(c) Increases by three
(d) Decreases by four
Q9. Cadmium rods are used in a nuclear reactor
(a) For promoting chain reaction
(b) For creating more neutrons
(c) For controlling the operation of the Nuclear reactor
(d) None of these
Q10. Graphite and heavy water are two common moderators used in a nuclear reactor. The function of the moderator is to
(a) Slow down neutrons
(b) Absorb neutrons
(c) Cool the reactor
(d) Arrest the chain reaction
Q11. Good conductors have many loosely bound –
(a) atoms
(b) protons
(c) molecules
(d) electrons
Q12. Astigmatism can be corrected by –
(a) Bifocal lenses
(b) Cylindrical lenses
(c) Concave lenses
(d) Plano-convex lenses
Q13. The half-life of a radioactive substance depends upon
(a) Its temperature
(b) The external pressure
(c) The mass of the substance
(d) None of these
Q14. The nucleus of an atom consists of
(a) Protons + electrons
(b) Only protons
(c) Protons + neutrons + electrons
(d) Protons and neutrons
Q15. Which of the following type of radiation does not originate within the nucleus?
(a) Alpha
(b) Beta
(c) Gamma
(d) X-rays
