Physics MCQs

Notes:
The Vernier caliper has a main scale and a sliding vernier scale which can measure nearest to 0.02 mm. It can be used to measure internal and the external dimensions of an object by using the smaller jaws at the top and the main jaws respectively. By using stems depth can be measured.

Notes:
Atmospheric pressure is the force that causes liquid to rise in a syringe when the piston is pulled up. When the syringe is placed with its opening in a liquid and the plunger is pulled up, the air pressure inside the barrel becomes much less than the atmospheric pressure acting on the liquid. Fluids flow from a high pressure area to a low pressure area. Once the pressure inside the syringe is lower than the pressure outside the syringe, the fluid will flow into the syringe.

Notes:
Conservation of Linear Momentum law says that if no external force acts on a system, then its total linear momentum remains conserved. In equation form, Momentum=mass*velocity. To increase the momentum of an object, we need to either increase its mass or velocity or both.

• Rockets work on law of conservation of momentum. As momentum in one direction is given to the rocket’s exhaust gases, momentum in the other direction is given to the rocket itself.

Notes:
Ultra High Frequency (UHF) designates the ITU radio frequency range of electromagnetic waves between 300 Megahertz to 3 GHz (3,000 Megahertz).

Notes:
C.V Raman discovered the Inelastic scattering of light by molecules in 1928, also named as ‘Raman effect’ Raman scattering is the inelastic scattering of a photon by molecules which are excited to higher vibrational or rotational energy levels. He was the first Indian Physicist to win the Nobel Prize for Physics in 1930. C.V Raman has also been bestowed with the Bharat Ratna Award.

Notes:
Steradian is the unit of Solid Angle (Angle in Space). One steradian is defined as the solid angle of a sphere subtended at the centre of a sphere by that surface of the surface whose area is equal to the square of the sphere’s radius. Its symbol is sr.

Notes:
The centripetal force and centrifugal force are equal in magnitude and have opposite direction. Centrifugal force can be regarded as the reaction of centripetal force.

Notes:
The inertial mass of a body may be measured as the ratio of the magnitude of the external force applied on it to the magnitude of acceleration produced in its motion. It is the measure of ability of the body to oppose the production of acceleration in its motion by an external force.

Notes:
The centre of gravity of the fluid which is displaced by an object is known as centre of buoyancy. For stable equilibrium for floating body, the line joining the centre of gravity of the body and centre of floatation should be vertical.

Notes:
Specific gravity is a unitless quantity. Specific gravity is the ratio of two same dimensions. The dimensions of density is M¹ L^{– 3}