Class 11th

Two trains 101 m and 99 m in length are running in opposite direction with velocities 54 km/h and 36 km/h. In what time they will completely cross each other?

The Boolean equation for the circuit as shown in figure is

 

When light of maximum wavelength 300 nm falls on a photoelectric emitter, photoelectrons are liberated. For another emitter however light of maximum wavelength 600 nm causes photoelectric emission. The ratio of work functions of first emitter to second emitter will be

The fringe width in Young's double slit experiment increases when

A heavy rope is suspended from rigid support. A wave pulse is set up at the lower end. Then

An object on a spring vibrates in a simple harmonic motion at a frequency of 4 hertz and an amplitude of 8 cm. If the mass of the object is 200 g, the spring constant is

The root mean square speed of molecules of a gas is 1260 m/s. The average speed of the gas molecules is

An ideal engine whose efficiency is 40%, receives heat at 500 K. If required efficiency is 50%, then intake temperature for the same exhaust temperature is

Choose the correct statement.

In a thermodynamic process, pressure of fixed mass of a gas is changed in such a manner that the gas releases 20 J of heat and 8 J of work is done on the gas. If initial internal energy of the gas was 40 J, what will be final internal energy?