Alternating Current (AC) is more advantageous than direct current because
it can be transmitted easily and efficiently
Alternating Current (AC) loses the least amount of energy when transmitted at high voltages
Alternating Current (AC) voltage can be easily increased or decreased
all the above
Correct Answer :
D. all the above
Related Questions
When a body Is taken to the poles from the equator, Its weight becomes
greater
less
the same
None of these
Mica is used in an electric iron because it is a
good conductor of heat
good conductor of electricity
bad conductor of electricity
Both (a) and (b) above
Besides protons, the nucleus of an atom contains
electrons
neutrons
neutrons and electrons
electrons, neutrons and other particles
The numerical reading of the Fahrenheit thermometer of a given temperature
is proportional to that of the Celsius thermometer
is always greater than that of the Celsius thermometer
is always less than that of the Celsius thermometer
may be greater than or less than or equal to that of the Celsius thermometer
In a longitudinal wave, the direction of propagation of the wave is
the same as the direction of the vibrations of the vibrating body
at right angles to the direction of the vibrations of the vibrating body
Both (a) and (b) above
None of the above
The period of a geostationary (synchronous) satellite orbiting the earth over the equator la
16 hours
12 hours
20 hours
24 hours
The colour of the light which travels through glass with minimum speed is
red
violet
green
yellow
When a body is immersed in a fluid the force of buoyancy of the fluid on the body depends on
the immersed volume of the body
density of the liquid
acceleration due to the gravity at the place
All the above
The velocity of sound in air increases with
the rise of temperature
rise of its frequency
decrease in humidity
fall of temperature
Cosmic rays are
powerful X-rays falling on the earth from space
ultraviolet rays from the sun
gamma rays from radioactive minerals
very energetic radiation falling upon the earth from outer space consisting chiefly of charged particles
The characteristics of a musical note are
loudness
pitch
quality or timbre
All the above
An ammeter has
a high resistance
a very low resistance
no resistance at all
resistance of 400 � w
In experiments on static electricity the standard method for obtaining small amounts of positive electricity is to rub
a glass rod with flannel
an abonite rod with flannel
a glass rod with silk
Any of the above
When one enters a dark room after being in bright light one is not able to see anything clearly for a while because
the retina of the eye moves forward
the retina of the eye moves backward
c).the iris is unable to dilate the pupil immediately to be able to see things
the eye has no power of accommodation
The brightest star visible to the naked eye is
Sirius
Vega
Rigel
Proxima Centauri
When the velocity of a body is halved
its momentum is halved
its kinetic energy is halved
its acceleration is halved
its potential energy is halved
Which of the following is not electromagnetic waves?
heat waves
sound waves
radio waves
light waves
The difference between planets and stars is
planets do not have light of their own whereas stars shine by their own light
planets do not twinkle like stars
planets are much smaller than stars
All the above
The acoustical quality of a room depends on
the size and shape of the room
the ability of the ceiling, walls and floor to exclude unwanted sound
the use of furnishings made of sound absorbing materials
All the above
Out of the following which is an insulator?
Silver
Copper
Nichrome
Dry wood
An electric fan converts
electrical energy into heat energy
electrical energy into mechanical energy
mechanical energy into electrical energy
mechanical energy into heat energy
The loudness of a sound is determined by
Frequency
Amplitude
Speed
Wavelength
When we tighten the string of a sitar or tanpura its pitch
remains the same
increases
decreases
None of the above
Increase in pressure
increases the melting point of ice
decreases the melting point of ice
has no effect on the melting point of ice
increases the volume of the ice
The radiator in a car serves to
cool the engine
heat up the engine
start the car
moderate the speed
X-rays are used
in hospital in the treatment of malignant growth
to reveal hidden flaws in metal castings and welded joints
to detect alterations made in works of art
All the above
At what temperature do the Fahrenheit and Celsius scales give the same reading?
212°
32°
-40°
0°
Which of the following is wrongly matched?
electric current - ampere
resistance - Ohm
electric power - volt
electric charge Coulomb
The audible range of a normal human ear is frequencies ranging from
10000 to 20000 Hz
50 to 15000 Hz
20 to 20000 Hz
15 to 50000 Hz
An electric kettle used for boiling hard water has a white scale deposited on its heating element. This consists or
sugar
sodium carbonate
common salt
carbonates of calcium and magnesium