Thermal Properties of Matter — Physics STD 11 Science — Question

An electric lamp and a candle produce equal illuminance at a photometer screen when they are placed at 80cm and 20cm from the screen respectively. The lamp is now covered with a thin paper which transmits 49% of the luminous flux. By what distance should the lamp be moved to balance the intensities at the screen again?

Why do we use shock absorbers in automobiles?

Give dimensions of Solar Constant and Water Equivalent.

Can a hydrogen atom emit characteristic X-rays?

What is momentum and on which factors it depends?

A scooter weighing 150kg together with its rider moving at 36km/ hr is to take a turn of radius 30m. What horizontal force on the scooter is needed to make the turn possible?

The coefficient of performance of a refrigerator depends on which factor?

A wire is stretched by a certain amount under a load. If the load and radius both are increased to four times, find the stretch caused in the wire.

Fill in the blanks using the word (s) from the list appended with statement: For solids with elastic modulus of rigidity, the shearing force is proportional to . . . while for fluids it is proportional to . . . (shear strain/ rate of shear strain).

Which measurement is more accurate between vernier callipers and screw gauge?