Uttarakhand Board Class 11 Physics — Flashcards for Quick Revision

A: A unit is a basic, arbitrarily chosen, internationally accepted reference standard used for comparison when measuring any physical quantity. We need units because: 1. To express the result of measurem

A: **Fundamental Units:** - Units for base quantities that cannot be expressed in terms of other units - Examples: meter (m) for length, kilogram (kg) for mass, second (s) for time **Derived Units:** -

A: The seven SI base units are: 1. **Length** - meter (m) 2. **Mass** - kilogram (kg) 3. **Time** - second (s) 4. **Electric Current** - ampere (A) 5. **Thermodynamic Temperature** - kelvin (K) 6. **Amo

A: Elasticity is the property of a body by virtue of which it tends to regain its original size and shape when the applied force is removed. Example: A helical spring that returns to its original length

A: Elasticity: Body regains original shape when force is removed (like spring). Plasticity: Body gets permanently deformed and doesn't return to original shape (like putty or mud).

A: Stress is the restoring force per unit area developed in a body when it is deformed. Formula: Stress = F/A, where F is the applied force and A is the cross-sectional area. SI unit: N/m² or Pascal (Pa)

A: Motion is the change in position of an object with time. An object is said to be in motion if its position changes with respect to time. Motion is described relative to a chosen reference point or ori

A: Rectilinear motion is the motion of an object along a straight line. Examples: (1) A car moving on a straight road, (2) A ball falling vertically downward under gravity, (3) Motion of a lift in a buil

A: Displacement is the change in position of an object. It is given by Δx = x₂ - x₁. Displacement is a vector quantity (has direction) and can be positive, negative, or zero. Distance is the actual path