Q1. When a ship floats on water
(a) it displaces no water
(b) the mass of water displaced is equal to the mass of the ship
(c) the mass of water displaced is lesser than the mass of the ship
(d) the mass of water displaced is greater than the mass of the ship
Q2. A long jumper runs before jumping because he
(a) covers a greater distance
(b) maintains momentum conservation
(c) gains energy by running
(d) gains momentum
Q3. A body is thrown vertically upwards and then falls back on the ground. Its potential energy is maximum
(a) on the ground
(b) at the maximum height
(c) during the return journey
(d) both on the ground and at the maximum height
Q4. A jet engine works on the principle of conservation of
(a) linear momentum
(b) angular momentum
(c) energy
(d) mass
Q5. One feels heavier in a lift when the lift
(a) is going down steadily
(b) just begins to go up
(c) is moving up steadily
(d) descends freely
Q6. The lift of an air plane is based on
(a) Torricelli’s theorem
(b) Bernoulli’s theorem
(c) Law of gravitation
(d) Conservation of linear momentum
Q7. The working principle of a washing machine is
(a) centrifugation
(b) dialysis
(c) reverse osmosis
(d) diffusion
Q8. Consider the following statements in respect of a jet engine and a rocket:
1. A jet engine uses the surrounding air for its oxygen supply and so is unsuitable for motion in space.
2. A rocket carries its own supply of oxygen in the gas form as a fuel.
Which of the above statement(s) is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Q9. Match List-I with List -II and select the correct answer using the codes given below the lists:
List-I
A. Wavelength
B. Energy
C. Intensity of sound
D. Frequency
List-II
1. Hertz
2. Angstrom
3. Joule
4. Decibel
Codes:
A B C D
(a) 2 3 4 1
(b) 1 2 3 4
(c) 2 3 1 4
(d) 2 1 3 4
Q10. Match List-I with List-II and select the correct answer with the help of codes given below:
List-I
A. Temperature
B. Power
C. Pressure
D. Force
List-II
1. Kelvin
2. Watt
3. Pascal
4. Newton
Codes:
A B C D
(a) 2 1 3 4
(b) 1 2 4 3
(c) 1 2 3 4
(d) 2 1 4 3
Solutions:
S1. Ans. (b)
Sol. According to Archimede’s principle when a body is immersed fully or partially in a liquid, it experiences an upward force that is equal to the weight of the fluid displaced by it therefore the mass of water displaced is equal to the mass of the ship.
S2. Ans. (b)
Sol. A long jumper runs before jumping to maintain momentum. This helps in jumping higher and longer because of inertia of motion gained due to the motion.
S3. Ans. (b)
Sol.We know that Potential energy = mgh
Hence potential energy is maximum at the maximum height.
S4. Ans. (a)
Sol. A jet engine works on the principle of conservation of linear momentum. In jet engines, a large volume of gases produced by the combustion of fuel is allowed to escape through a jet in the backward direction.
Due to the very high speed or velocity, the backward rushing gases have a very large momentum.
S5. Ans. (b)
Sol. One feels heavier in a lift when the lift just begins to go up because our body gains inertia from the position of rest and pushes up against the gravity so here the weight becomes zero and our mass makes us feel heavier.
S6. Ans. (b)
Sol. Bernoulli’s theorem
S7. Ans. (a)
Sol. Washing machine works on the principle of centrifugation. Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures with a centrifuge, used in industry and in laboratory settings. More-dense components of the mixture migrate away from the axis of the centrifuge, while less-dense components of the mixture migrate towards the axis.
S8. Ans. (c)
Sol. In respect of a jet engine and a rocket, both the given statements are correct.
S9. Ans. (a)
Sol. Wavelength is the distance between two consecutive crests or troughs and 1 angstrom = 10-10m, joule is the unit of energy. Intensity of sound is measured in decibel. Frequency is measured in hertz (Hz).
S10. Ans. (c)
Sol.The unit of temperature is kelvin, power is measured in watt, pressure in pascal and force in newton.
