A spherical mirror is
a reflecting elliptical portion
a reflecting spherical surface
a parabolic reflecting surface
a flat reflecting surface
Correct Answer :
B. a reflecting spherical surface
Related Questions
The maximum displacement of the particle in a mechanical wave motion is known as
amplitude
vibration
frequency
phase
The Milky Way is
the path of a star which is nearest to the earth
a galaxy which includes the sun
a star that is nearest to the earth
None of these
When a bowler spins a ball, it changes its direction in the air. This is due to
turbulence caused by the wind
buoyancy of air
unequal pressures acting on it
sudden change in the direction of the wind
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
When a steel ball is placed on the surface of mercury, it does not sink because
of the surface tension of mercury
mercury is a semi-solid
of the high viscosity of mercury
the density of mercury is greater than that of steel
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
A spherical mirror is
a reflecting elliptical portion
a reflecting spherical surface
a parabolic reflecting surface
a flat reflecting surface
When light travels from one medium to another there is a change in its
velocity
wavelength
frequency
Both (a) and (b) above
The heating element often used in an electric iron is
copper
tungsten
mica
nichrome
Sound travels fastest in
air
water
iron
vacuum
At what temperature do the Fahrenheit and Kelvin scales give the same reading?
212°
32°
-40°
0°
Fish and other aquatic creatures can live inside a deep frozen pond because
fish are cold-blooded animals
ice is a bad conductor of heat
there will always be water just beneath the ice level
they can adapt themselves to live in ice
The rocket engine is motivated by jet propulsion which uses the famous
Kepler's Laws
Newtonian Third Law of Motion
Bernoulli's Principle
Law of Relativity
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 end product in the uranium disintegration series is
lead
zinc
carbon
tin
The following are the atmospheric zones above the surface of the earth:
A) Troposphere
B) Ionosphere
C) Stratosphere
D) Exosphere
Select the correct sequence from the earth's surface on the basis of the codes given below:
ACBD
ABCD
CABD
BACD
If you want to open a door with les difficulty you push it
at the middle
at a point away from the hinge (near the rim)
near the hinge
None of the above
The atmosphere gets heated up mainly by
direct sun's rays
radiation from earth's surface
radiogenic heat (resulting from radioactive decay)
cosmic rays coming from space
A hydrogen bomb is based on
nuclear fusion
nuclear fission
Both (a) and (b) above
Neither (a) nor (b)
Stars twinkle because of
refraction of light from them through air
reflection
absorption
All the above
The property of a fluid by which it resists relative motion within itself is known as
cohesive force
surface tension
diffusion
viscosity
When the disturbed electrons of an exited atom transfer back into lower energy levels they emit energy in the form of electromagnetic wave pulses called
neutrons
electrons
phonons
photons
The brightest star visible to the naked eye is
Sirius
Vega
Rigel
Proxima Centauri
Pyrometers are instruments used
for measuring the velocity of wind
in the manufacture of fireworks
in finding the coefficient of apparent expansion of a liquid
for measuring high temperatures
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle
Which of the following wires of same dimensions offers least resistance to the ,flow of current?
copper
aluminium
silver
nichrome
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
For an electron orbiting in a hydrogen atom, the necessary centripetal force keeping it in orbit is provided by
the electrical attraction between the negatively charged electron and the positively charged porton
the high speed of the electron
the low speed of the electron
gravity
Velocity of sound in high altitudes is low because at such a height
the temperature is low
there is no air
the pressure is low
All the above
What is the minimum velocity required for a rocket to overcome earth's gravity and travel into space?
18 km/sec
11.2 km/ sec
21 km/ sec
35 km/ sec