Q1. An example of natural magnet is
(d) all of these
Q2. The ability to do work is called
Q3. The SI unit of area is
Q4. What does angstrom measure?
(a) Quantity of liquid
(b) Length of light waves
(c) Length of cables
(d) Speed of ships
Q5. Friction can be increased by
(a) Applying oil
(b) Moisture on the surfaces
(c) Rough surfaces
(d) all of these
Q6. A feather weighing 5 gm and a nail weighing 10 gm have the same kinetic energy. Which of the following statement is true about the momentum of the two bodies?
(a) Both will have equal momentum
(b) It is not possible to compare the momentum
(c) The lighter body will have higher momentum
(d) The heavier body will have higher momentum
Q7. An air bubble inside water behaves like a
(a) Plano-convex lens
(b) Concave mirror
(c) Concave lens
(d) Convex lens
Q8. Bakelite is used in making electrical appliances because it is a
(a) Good conductor for electricity
(b) Good insulator of electricity
(d) Good conductor of heat
Q9. LED and CFL are commonly used as sources of light in homes. Which of the following statement is true?
(a) Both are equally good
(b) Neither of them is good because both contain toxic materials
(c) CFL is better because LED contains toxic materials
(d) LED is better because CFL contains toxic materials
Q10. In which of following cases of motion, are the distance moved and the magnitude of displacement equal?
(a) A pendulum oscillating
(b) The Earth revolving around the Sun
(c) A car moving on a straight road
(d) A car moving in a circular path
Sol. An example of a natural magnet is the lodestone, also called magnetite.
Sol. Energy is the ability to do work.
Sol. the standard unit of area is the square metre (written as m2).
Sol. Angstrom (Å), unit of length used chiefly in measuring wavelengths of light.
Sol. By making the surface rough, friction force can be increased.
Sol. the air bubble in water should behave as a concave lens.
Sol. Electric switches are made of Bakelite because it is a poor conductor of heat and electricity.
Sol. CFL bulbs are a type of fluorescent lamp they contain mercury, which is toxic and complicates the disposal of CFL bulbs.
Sol. the displacement is always equal to the distance, when an object is moving in the a straight path (displacement is defined as the shortest distance covered by a body).