Units and Measurements — Physics STD 11 Science — Question

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.

The displacement-time graph for two particles X and Y are straight lines making angles of 30° and 60° with the time axis. What is the ratio of the velocities of Y and X?

Explain why
Atmospheric pressure at a height of about 6km decreases to nearly half of its value at the sea level, though the height of the atmosphere is more than 100km.

Given a + b + c + d = 0, which of the following statements are correct:

b + c must lie in the plane of a and d if a and d are not collinear, and in the line of a and d, if they are collinear?

Sometimes, when an automobile picks up speed, its body begins to rattle. Why?

Two resistors having equal resistances are joined in series and a current is passed through the combination. Neglect any variation in resistance as the temperature changes. In a given time interval:

1. Equal amounts of thermal energy must be produced in the resistors.
2. Unequal amounts of thermal energy may be produced.
3. The temperature must rise equally in the resistors.
4. The temperature may rise equally in the resistors.

Why are gas thermometers more sensitive than mercury thermometers?

A long solenoid is fabricated by closely winding a wire of radius 0.5mm over a cylindrical nonmagnetic frame so that the successive turns nearly touch each other. What would be the magnetic field B at the centre of the solenoid if it carries a current of 5A?

What is the frequency of variation of potential or kinetic energy when the frequency of the oscillation is f?

Can the temperature of an isolated system change?