Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

Consider two observers moving with respect to each other at a speed v along a straight line. They observe a bock of mass m moving a distancel on a rough surface. The following quantities will be same as observed by the two observers.

1. Kinetic energy of the block at time t.
2. Work done by friction.
3. Total work done on the block.
4. Acceleration of the block.

Let V and E denote the gravitational potential and gravitational field at a point. It is possible to have:

1. V = 0 and E = 0
2. V = 0 and E ≠ 0
3. V ≠ 0 and E = 0
4. V ≠ 0 and E ≠ 0

The ratio of the longest to shortest wavelengths in Brackett series of hydrogen spectra is

If a proton is projected in a direction perpendicular to a uniform magnetic field with velocity v and an electron is projected along the lines of force, what will happen to proton and electron(a) The electron will travel along a circle with constant speed and the proton will move along a straight line(b) Proton will move in a circle with constant speed and there will be no effect on the motion of electron(c) There will not be any effect on the motion of electron and proton(d) The electron and proton both will follow the path of a parabola

Which source is associated with a line emission spectrum (a) Electric fire(b) Neon street sign(c) Red traffic light(d) Sun

Sun maintains its shining because of:

Consider the situation shown in figure. The wire AB is slid on the fixed rails with a constant velocity. If the wire AB is replaced by a semicircular wire, the magnitude of the induced current will: 

1. Increase.
2. Remain the same.
3. Decrease.
4. Increase or decrease depending on whether the semicircle bulges towards the resistance or away from it.

The maximum value of stopping potential in the following diagram is