An ammeter has
a high resistance
a very low resistance
no resistance at all
resistance of 400 � w
Correct Answer :
B. a very low resistance
Related Questions
The heat produced in a conductor due to the passage of a current through it is proportional to
the square of the current
the resistance of the conductor
the time for which the current flows
All the above
In the electrical circuit of a house the fuse acts as
a thermopile
a load
a step down device
a safety device
The plants in a greenhouse are enclosed in a glass enclosure because
glass allows the heat radiations of shorter wavelengths from the sun to pass through
the plants absorb them - these shorter wavelengths - and reradiate them in the form of longer wavelengths
the longer wavelengths cannot penetrate through the glass walls
All the above
The transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison
The temperature of a large bucket-full of hot water (a few degrees below boiling point) is lower than a beaker full of boiling water. But
the hot water contains a much larger quantity of internal energy than the boiling water
the boiling water contains more quantity of internal energy than the warm water
both of them have got the same amount of internal energy.
nothing can be said definitely with the data given
The force that keeps a body in a circular motion la called
the centripetal force
the centrifugal force
the frictional force
All the above
A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that
the valve filaments have low resistance
valve-radio sets work at a higher voltage
transistor set has a low resistance
filaments of the valves cake time to beat up and function
The minimum velocity required by a satellite to escape earth's gravitational pull is
18 km/s
11.2 km /s
21 km/s
35 km/s
A lactometer la used to
find out the specific gravity of liquids
measure the volumes of liquids
test the purity of milk
determine the strength of acid in car batteries
Drinks kept in a vacuum flask remain hot or cold as the case may be for a long time because
both walls are silvered on the vacuum side
there is vacuum between the double walls
the cork is a poor conductor of heat
of all the above
The enormous energy released in nuclear and thermonuclear reactions is due to conversion of
chemical energy into heat energy
mechanical energy into heat energy
protons into neutrons
mass into energy according to Einstein's equation
The base of an electric iron is brightly polished mainly
to make it smooth and frictionless
to make it rust - proof
to reduce heat loss by radiation
to make it more durable
A projectile is fired at an angle with the horizontal with a small velocity. Its horizontal range will be maximum when the angle with the horizontal is
0°
30°
45°
60°
The solar wind is composed of
outward stream of protons and electrons on the surface of the sun during solar flares and sun-spot activity
plasma
ionized gas
All of these
For viewing objects placed at a higher level from a position at a lower level, the instrument used' Is known aa
telescope
spectrometer
microscope
periscope
When temperature decreases, resistance of metals to flow of electricity
increases
decreases
neither increases nor decreases
first increases then decreases
Moon has no atmosphere because
it has no population
it is quite far off
its surface is full of rocks
its gravity is not sufficient for any atmosphere to hold on to it
The direction of heat flow between two objects depends on
their heat contents
their masses
their temperatures
whether they are in solid, liquid or gaseous state
If you want a sound proof room, the walls should be
able to refract the sound
good absorbers of sound
good reflectors of sound
All the above
The image of an object formed in a plane mirror
is real
is virtual
can be obtained on a screen
is slightly bigger than the object
A lightning conductor installed in a building
does not allow the lightning to fall on the building at all
drives away the charged clouds
forces the lightning to fall on other buildings near that building
conducts the electric charges to the ground when lightning strikes the building
When light travels from one medium to another there is a change in its
velocity
wavelength
frequency
Both (a) and (b) above
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
A wire conveying a current deflects a pivoted magnetic needle. This was discovered by
Marconi
Oersted
Faraday
Ohm
Heat transfer
cools the body that transfers it
heats the body that absorbs the heat
may change the physical state of the substance
All the above
The heat generated in a conductor carrying current is proportional to
the resistance
the square of the current flowing through it
the time the current flows
All the above
In the case of bodies falling under gravity which of the following remains constant at a given place?
kinetic energy
potential energy
acceleration
All the above
Of the following types of electromagnetic radiation which has the longest wavelength?
ultraviolet rays
gamma rays
radio waves
infrared waves
The stem of a vibrating tuning fork is pressed against a sound box. Then
the loudness of the sound increases
the loudness remains the same
the loudness decreases
the sound suddenly stops
The weight of a body is
maximum at the equator
minimum at the equator
minimum at the poles
the same everywhere