Waves — Physics STD 11 Science — Question

If the magnetic field outside a copper box is suddenly changed, what happens to the magnetic field inside the box? Such low-resistivity metals are used to form enclosures which shield objects inside them against varying magnetic fields.

Name two absolute units of force. How are they related?

Is it possible to have interference between the waves produced by two violins? Why?

Give the magnitude and direction of the net force acting on.
A car moving with a constant velocity of 30km/h on a rough road.

Why is air used instead of Namde for thermal insulation?

Answer the following questions based on the P-T phase diagram of carbon dioxide

1. At what temperature and pressure can the solid, liquid and vapour phases of CO₂ co-exist in equilibrium ?
2. What is the effect of decrease of pressure on the fusion and boiling point of CO₂?
3. What are the critical temperature and pressure for CO₂? What is their significance?
4. Is CO₂ solid, liquid or gas at (a) –70 °C under 1 atm, (b) –60 °C under 10 atm, 15 °C under 56 atm?

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 mid-point of AB going towards A.

Find the number of joules in a kilowatt hour.

A ball is dropped from a height of 90m on a floor. At each collision with the floor, the ball loses one tenth of its speed. Plot the speed-time graph of its motion between t = 0 to 12s.

Read each statement below carefully and state, with reasons, if it is true or false:
The acceleration vector of a particle in uniform circular motion averaged over one cycle is a null vector.