Units and Measurements — Physics STD 11 Science — Question

An experimenter measures the length of a rod. Initially the experimenter and the rod are at rest with respect to the lab. Consider the following statements:

1. If the rod starts moving parallel to its length but the observer stays at rest, the measured length will be reduced.
2. If the rod stays at rest but the observer starts moving parallel to the measured length of the rod, the length will be reduced.

1. Is true but B is false.
2. B is true but A is false.
3. Both A and B are true.
4. Both A and B are false.

Define impulse and tell its unit

A metal bar of length L, area of cross-section A, Young's modulus Y and coefficient of linear expansion a, is clamped between two stout pillars. What is the force exerted by the bar when it is heated through t°C?

Which law is to be used by a man stranded at the middle of a pond, when no friction is experienced by the boat?

The normal duration of I.Sc. Physics practical period in Indian colleges is 100 minutes. Express this period in microcenturies. 1 microcentury = 10^-6 × 100 years. How many microcenturies did you sleep yesterday?

In a number without decimal, what is the significance of zeros on the right of non-zero digits?

The heat developed in a system is proportional to the current through it:

1. It cannot be Thomson heat.
2. It cannot be Peltier heat.
3. It cannot be Joule heat.
4. It can be any of the three heats mentioned above.

Why should the amplitude of the vibrating pendulum be small?

What is the efficiency of a Carnot engine operating between boiling and freezing points of water?