Question: The freezing point of fresh water is –
1. 0°C
2. 4°C
3. 3°C
4. 5°C
Answer: 1
Question: Flywheel is an important part of a steam engine because it –
1. gives strength to the engine
2. accelerates the speed of the engine
3. helps the engine in keeping the speed uniform
4. decreases the moment of inertia
Answer: 3
Question: A device which converts AC into DC is known as –
1. Transformer
2. Amplifier
3. Rectifier
4. Stabiliser
Answer: 3
Question: Superconductivity means –
1. very feeble currect
2. very large current
3. current without facing any resistance
4. current due to positive particles
Answer: 3
Question: Angular momentum is equal to –
1. moment of inertia x angular velocity
2. mass x angular velocity
3. linear velocity x angular velocity
4. mass x linear velocity
Answer: 1
Question: Which one of the following SI units is not correctly matched?
1. Work – Joule
2. Mass – Kg
3. Force – Newton
4. Pressure – Dyne
Answer: 4
Question: An air bubble in water will act like a –
1. Convex mirror
2. Concave lens
3. Concave mirror
4. Convex lens
Answer: 4
Question: The highest temperature attained y a super conductor is –
1. 24 K
2. 133 K
3. 150 K
4. 300 K
Answer: 2
Question: The radio isotope used in the detection of tumour is –
1. Arsenic – 74
2. Cobalt – 60
3. Sodium – 24
4. Carbon – 14
Answer: 2
Question: Bats can fly in the dark, because –
1. They have better vision in the dark
2. The pupils of their eyes are very big
3. They are guided by ultrasonic waves produced by them
4. None of the above
Answer: 3
Question: The sky appears blue, because –
1. It is actually blue
2. The Atmosphere scatters blue colours more than the others
3. All colours interfere to produce blue
4. In white light the blue component dominates
Answer: 2
Question: A thermostat is a device for –
1. Switching off an electrical appliance
2. Measuring temperature
3. Regulating temperature
4. Producing Heat
Answer: 3
Question: A football bounces when it falls on the ground, because –
1. It is made up of Rubber
2. It is hollow
3. It is very light and is able to overcome the resistance of air
4. Of its property of elasticity
Answer: 4
Question: Raindrops are spherical due to –
1. Viscosity of water
2. Surface tension
3. Continuous evaporation
4. Air friction
Answer: 2
Question: Atmospheric pressure is measured with a –
1. Hydrometer
2. Barometer
3. Hygrometer
4. Altimeter
Answer: 2