Car rear view mitrrors carry a warning message that" objects in the rear view mirror are closer than they appear". Why do you think this is so?

A convex rear view mirrors is preferred over a plane mirror in a car. Why?

The spherical mirror used as a rear view mirror in the vehicle is

Pick out the concave and convex mirrors from the following and tabulate them Rear-view mirror, Dentist's mirror, Torch-light mirror, Mirrors in shopping malls, Make-up mirror.

Suppose while sitting in a parked car, you notice a jogger approaching towards you in the side view mirror of R = 2m. If the jogger is running at a speed of 5 ms^(-1) , how fast the image of the jogger appears to move when the jogger is (a) 39 m (b) 29 m (c) 19m (d) 9 m aways.

Read the following passage and answer the questions that follow Rahini and her parents were waching a televison programme . An advertisement flashed on the screen which was promoting use of sanitary napkins . Rahini's parents suddenly changed the channel , but she objected to her parents and explained the need and importance of such advertisment . Do you think that Rahini's objection towards her parents was correct ? If so , why ?

Assertion and Reason. Mark the correct choice as:Assertion: Convex mirror are used as rear view mirror in vehicles for observing traffic at our back.Reason: A convex mirror has a much larger field of view.

Explain why a test tube immersed at a certain angle in a tumbler of water appears to have a mirror suface for a certain viewing position? (AS_(7))

RuBisCo is an enzyme that acts both as a carboxylase and oxygenase. Why do you think RuBisCo carries out more carboxylation in C_(4) plants?

Answer the following questions . a. The earth's magnetic field varies from point is space. Does it also change with time ? It so , on what time scate does it change appreciably ? b. The earth's core is known to contain iron. Yet geologists do not regard this as a source of the earth's magnetism why ? c. The charged currents in the outer conducting regions of the earth's core are thought to be responsible for earth's magnetism . What might be the ' battery ' (i.e., the source of energy) to sustain these currents ? d. The earth may have even reversed the direction of its field several times during its history of 4 to 5 billion years. How can geologists know about the earth's field in such distant past ? e. The earth's field departs from its dipole substantially at large distances (greater than about 30,000 km) what agencies may be responsible for this distortion ? f. Interstellar space has an extremely weak magnetic field of the order of 10^(-12) T, Can such a weak field be of any significant consequence ? Explain. [Note : Exercise 2 is meant mainly to arouse your curiosity . Answers to some question above are tentative or unknown . Brief answers wherever possible are given at the end . For details , you should consult a good text on geomagnetism.]