CDS Questions
An optician prescribes a power = -0.5 dioptre
An optician prescribes a power = - 0.5 dioptre. The corresponding lens must be a
- convex lens of focal length 2 m
- concave lens of focal length 50 cm
- concave lens of focal length 2 m
- convex lens of focal length 50 cm
If the speed of light in air is 3 x 108 m/s, the speed of light in glass
If the speed of light in air is 3 x 108 m/s, the speed of light in glass (with refractive index 1.5) would be
- 4.5 x 108 m/s
- 1.5 x 108 m/s
- 2 x 108 m/s
- 3 x 108 m/s
While looking at the image formed by a convex lens
While looking at the image formed by a convex lens (one half of the lens is covered with black paper), which one of the following will happen to the image?
- Half of the image will be visible
- One can see an image of smaller size
- Intensity of the image will be diminished
- Image will be inverted
A sound wave has frequency of 2 kHz and wavelength of 35 cm
A sound wave has frequency of 2 kHz and wavelength of 35 cm. If an observer is 1.4 km away from the source, after what time interval could the observer hear the sound?
- 0.5 s
- 2 s
- 4 s
- 20 s
Ultrasonic waves of frequency are passed through a medium
Ultrasonic waves of frequency 3 × 105 Hz are passed through a medium where speed of sound is 10 times that in air (Speed of sound in air is 300 m/s). The wavelength of this wave in that medium will be of the order of
- 0.1 cm
- 1 cm
- 10 cm
- 100 cm
A current-carrying wire is known to produce magnetic lines of force
A current-carrying wire is known to produce magnetic lines of force around the conducting straight wire. The direction of the lines of force may be described by
- left-hand thumb rule for up-current and right-hand thumb rule for down current
- right-hand thumb rule for both up and down currents
- right-hand thumb rule for up-current and left-hand thumb rule for down current
- left-hand thumb rule for both up and down currents
During Short circuiting, the current flowing in the electrical circuit
During Short circuiting, the current flowing in the electrical circuit
- increases instantaneously
- reduces substantially
- varies continuously
- does not change
A cyclotron accelerates particles of mass m and change q
A cyclotron accelerates particles of mass m and change q. The energy of particles emerging is proportional to
- q/m2
- q2/m
- q2/m2
- q
The electric field inside a perfectly conducting hollow object is
The electric field inside a perfectly conducting hollow object is
- infinite
- 4π
- dependent upon the shape of the object
- zero
Van de graaff generator is used for
Van de graaff generator is used for
- generating large currents
- accelerating charged particles
- generating electric field
- generating high-frequency voltage
Two conducting wires A and B are made of same material
Two conducting wires A and B are made of same material. If the length of B is twice that of A and the radius of circular cross-section of A is twice that of B, then their resistances RA and RB are in the ratio
- 1 : 2
- 2 : 1
- 1 : 4
- 1 : 8
A force F, acting on an electric charge q, in presence of an electromagnetic field
A force F, acting on an electric charge q, in presence of an electromagnetic field, moves the charge parallel to the magnetic field with velocity v. Then F is equal to (where E and B are electric field and magnetic field respectively)
- q(v x B)
- q(v x E)
- qB
- qE
Which one of the following circuit elements is an active component
Which one of the following circuit elements is an active component?
- Transistor
- Capacitor
- Resistor
- Inductor
A fuse is used in the electric circuit to
A fuse is used in the electric circuit to
- break the circuit when power gets off
- complete the circuit for flow of current
- break the circuit when excessive current flows through the circuit
- indicate if the current is flowing uninterrupted
The Celsius temperature is
The Celsius temperature is a/an
- approximate temperature
- absolute temperature
- specific temperature
- relative temperature
A close bottle containing water at room temperature
A close bottle containing water at room temperature was taken to the Moon and then the lid is opened. The water will
- boil
- freeze
- not change at all
- decompose into oxygen and hydrogen
Heat given to a body which raises its temperature by
Heat given to a body which raises its temperature by 1°C is known as
- water equivalent
- specific heat
- temperature gradient
- thermal capacity
Bats can fly in dark because they
Bats can fly in dark because they
- have strong wings
- have sharp eyes
- produce ultrasonic waves
- are nocturnal
If the door of a running refrigerator in a closed room is kept open
If the door of a running refrigerator in a closed room is kept open, what will be the net effect on the room?
- It will make the temperature go up and down
- It will make no difference on the average
- It will heat the room
- It will cool the room
Bernoulli's principle is based on which one among the following laws
Bernoulli's principle is based on which one among the following laws
- Conservation of momentum
- Conservation of angular momentum
- Conservation of energy
- Conservation of mass
Which of the following is not a result of surface tension
Which of the following is not a result of surface tension?
- Flow of a liquid
- Capillary rise
- Nearly spherical drop of rain
- Removal of dirt by soap or detergent
If the motion of an object is represented by a straight line
If the motion of an object is represented by a straight line parallel to the time axis in a distance-time graph, then the object undergoes
- decelerated motion
- uniform non-zero velocity motion
- accelerated motion
- zero velocity motion
A force applied on a body is represented as
A force applied on a body is represented as
F = 6i - 8j + 10k
and accelerates is at 1 m/s2. The mass of the body is
- 10√2 kg
- 2√10 kg
- 8 kg
- 10 kg
A passenger in a moving train tosses a coin upward which falls behind him
A passenger in a moving train tosses a coin upward which falls behind him. It implies that the motion of the train is
- uniform
- retarded
- accelerated
- along the circular tracks
Two bodies A and B having masses m and 4m respectively
Two bodies A and B having masses m and 4m respectively are moving with equal linear momentum. The ratio of kinetic energies between A and B is
- 1 : 2
- 1 : 1
- 4 : 1
- 1 : 4
The dimension of impulse is the same as that of
The dimension of impulse is the same as that of
- pressure
- angular momentum
- linear momentum
- work
A motor vehicle is moving on a circle with uniform speed
A motor vehicle is moving on a circle with uniform speed. The net acceleration of the vehicle is
- perpendicular to the radius and along the velocity
- towards the centre of circle
- away from the centre along the radius of the circle
- zero
If the distance S covered by a moving car in rectilinear motion
If the distance S covered by a moving car in rectilinear motion with a speed v in time t is given by S = vt, then the car undergoes
- uniform velocity
- uniform acceleration
- non-uniform acceleration
- non-uniform velocity
Two cars A and B have masses mA and mB respectively
Two cars A and B have masses mA and mB respectively, with mA > mB. Both the cars are moving in the same direction with equal kinetic energy. If equal braking force is applied on both, then before coming to rest
- A will cover a greater distance
- B will cover greater distance
- both will cover the same distance
- distance covered by them will depend on their respective velocities
Planet A has double the radius than that of planet B
Planet A has double the radius than that of planet B. If the mass of planet A is 4 times heavier than the mass of planet B, which of the following statements regarding weight of an object is correct?
- Heavier on Planet B than on Planet A
- Same on both the Planets
- Cannot be measured on Planet B
- Heavier on Planet A than on Planet B
A bullet is fired vertically up from a 400 m tall tower with a speed
A bullet is fired vertically up from a 400 m tall tower with a speed 80 m/s. If g is taken as 10 m/s2, the time taken by the bullet to reach the ground will be
- 24 s
- 20 s
- 16 s
- 8 s
Within an animal cell, the most abundant inorganic constituent
Within an animal cell, the most abundant inorganic constituent of protoplasm is
- phosphate
- water
- sodium and potassium salt
- iron
The main thinking part of the brain is
The main thinking part of the brain is
- hypothalamus
- midbrain
- hindbrain
- forebrain
Which one of the following is not a function of liver
Which one of the following is not a function of liver?
- Production of urea
- Absorption of food and excess water from the undigested food
- Destruction of dead and worn-out red blood cells
- Conversion of glucose into glycogen
Which is not a part of female reproductive system
Which one of the following is not a part of female reproductive system?
- Cervix
- Vagina
- Urethra
- Fallopian tube
Balanced diet should have approximately
Balanced diet should have approximately
- 3/5 protein, 1/5 fat and 1/5 carbohydrate
- 1/5 protein, 1/5 fat and 3/5 carbohydrate
- 1/2 protein, 1/4 fat and 1/4 carbohydrate
- 1/5 protein, 3/5 fat and 1/5 carbohydrate
After diagnosis of disease in a person, the doctor advises the patient iron and folic acid tablets
After diagnosis of disease in a person, the doctor advises the patient iron and folic acid tablets. The person is suffering from
- goitre
- osteoporosis
- anaemia
- protein-energy malnutrition
Which is the correct electronic configuration of chlorine
Which one of the following is the correct electronic configuration of chlorine
- 7, 8, 2
- 2, 8, 7
- 2, 8, 8
- 2, 7, 8
The distribution of electrons into different orbits of an atom
The distribution of electrons into different orbits of an atom, as suggested by Bohr, is
- 2 electrons in the K-orbit, 8 electrons in the L-orbit, 32 electrons in the M-orbit
- 2 electrons in the K-orbit, 8 electrons in the L-orbit, 16 electrons in the M-orbit
- 2 electron in the K-orbit, 6 electrons in the L-orbit, 18 electrons in the M-orbit
- 2 electrons in the K-orbit, 8 electrons in the L-orbit, 18 electrons in the M-orbit
In the reaction ZnO + C → Zn + CO, 'C' acts as
In the reaction ZnO + C → Zn + CO, 'C' acts as
- an acid
- a base
- an oxidising agent
- a reducing agent
Which of the following acids is a mineral acid
Which of the following acids is a mineral acid
- Citric acid
- Ascorbic acid
- Tartaric acid
- Hydrochloric acid
Dihydrogen can be prepared on a commercial scale by
Dihydrogen can be prepared on a commercial scale by the action of steam on hydrocarbons, when a mixture of CO and H2 gas is formed. It is known as
- industrial gas
- producer gas
- fuel gas
- water gas
When carbon dioxide is passed through lime water
When carbon dioxide is passed through lime water, the solution turns milky, but, on prolonged passage, the solution turns clear. This is because
- the calcium carbonate formed initially is converted to soluble calcium bicarbonate on passage of more carbon dioxide
- the calcium bicarbonate formed initially is converted to soluble calcium carbonate on passage of more carbon dioxide
- the reaction is reversible and lime water is regenerated
- the initially formed insoluble compound is soluble in carbonic acid
What is the main constituent of a Pearl
What is the main constituent of a Pearl?
- Calcium carbonate and magnesium carbonate
- Calcium carbonate only
- Calcium sulphate only
- Calcium oxide and calcium sulphate
A nauticle mile is equal to
A nauticle mile is equal to
- 5060 feet
- 5280 feet
- 6060 feet
- 6080 feet
A person standing in front of a plane mirror approaches the mirror
A person standing in front of a plane mirror approaches the mirror by 40 cm. The new distance between the person and his image in the plane mirror is
- 60 cm
- 1.4 m
- 1.2 m
- 2.0 m
If two conducting spheres are separately charged
If two conducting spheres are separately charged and then brought in contact
- the total charge of the two spheres is conserved
- both the total energy and the total charge are conserved
- the final potential is always the mean of the original potential of the two spheres
- the total energy of the two spheres is conserved
When you pull out the plug connected to an electrical appliance
When you pull out the plug connected to an electrical appliance, you often observe a spark. To which property of the appliance is this related?
- Resistance
- Wattage
- Capacitance
- Inductance
Electricity is produced through dry cell from
Electricity is produced through dry cell from
- Nuclear Energy
- Mechanical Energy
- Chemical Energy
- Thermal Energy
A person having blood group 'A' can donate blood to
Which of the statements given below are correct?
- A person having blood group 'A' can donate blood to persons having blood group 'A' and blood group 'AB'.
- A person having blood group 'AB' can donate blood to persons having blood groups 'A', 'B', 'AB' or 'O'.
- A person with blood group 'O' can donate blood to persons having any blood group.
- A person with blood group 'O' can receive blood from the person of any of the blood groups.
Select the correct answer using the code given below:
- 1 and 3 only
- 3 and 4 only
- 1 and 2 only
- 1, 2, 3 and 4
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