PART - 1 CH - 1 Units and Measurements — Physics STD 11 Science — Question

Figure shows a glowing mercury tube. The intensities at point A, B and C are related as:

1. B > C > A
2. A > C > B
3. B = C > A
4. B = C < A

A stone is fastened to one end of a string and is whirled in a vertical circle of radius R. Find the minimum speed the stone can have at the highest point of the circle.

What is the luminous flux of a source emitting radio waves?

A particle is in linear simple harmonic motion between two points, A and B, 10cm apart. Take the direction from A to B as the positive direction and give the signs of velocity, acceleration and force on the particle when it is:
At the end A.

If oil of density higher than density of water is used in a resonance tube, how will the frequency change?

Define the effect of shape of the earth on the value of g.

When a pendulum clock gains time, what adjustment should be made?

Answer the following:
The casing of a rocket in flight burns up due to friction. At whose expense is the heat energy required for burning obtained? The rocket or the atmosphere?

Among the following quantities, select such pairs which have the same dimensions; momentum, angular velocity, torque, pressure, impulse, surface tension, stress, work, frequency, force constant.

State if the following statements is true or false. Give reasons for your answer:
Total energy of a system is always conserved, no matter what internal and external forces on the body are present.