The following is a list of some possible properties of high temperature superconductors. Some may be incorrect.
The figure below shows a straight wire carrying a steady current from X to Y. The wire is suspended between the poles of two similar permanent magnets, each of which produces a uniform magnetic field between the N and S poles.
A person stands on a scale in an elevator. He notices that the scale reading is lower than his normal ‘weight’. Which of the following could possibly describe the motion of the elevator?
A copper ring hangs vertically from a thread with its axis along the axis of a coil as shown in the diagram.
A simple DC motor has n turns of wire in the armature and has an area of A m2. A current of I amperes passes through the armature. The plane of the armature is at 0 o to the direction of the magnetic field of strength B Teslas. What is the torque on the armature if the area and the current are doubled and the armature is at an angle of 60 o to the magnetic field direction?
Astronauts on a long space journey are playing golf inside their spaceship, which is travelling away from the Earth with speed 0.6 c . One of the astronauts hits a drive exactly along the length of the spaceship (in its direction of travel) at speed 0.1 c in the frame of the spaceship. What is the speed of the golf ball as observed from Earth?
A moon of a planet Rusean has an orbital period of 5 days and is at a distance of 5 units from the centre of the planet. Another moon is discovered at a distance of 20 units from the centre of Rusean. Which of the following will be closest to the orbital period of the newly discovered moon?
Which statement, according to the BCS theory of superconductivity, is correct?
At room temperature, what is the current in an intrinsic semiconductor due to?
The Space Shuttle orbits 300 km above the Earth's surface. If the Earth's radius is 6400 km, what is the gravitational acceleration experienced by the Space Shuttle while in this orbit?
Inside a discharge tube producing cathode rays, a freely rotatable wheel is mounted. When cathode rays fall on it the wheel starts rotating. What does this experiment indicate about cathode rays?
AC induction motors are commonly used in small power tools around the home. Which of the following statements correctly describes the working of an AC induction motor?
A ball is projected horizontally with a speed of 40 ms-1 from the top of a cliff on the surface of the Earth. What will be its approximate speed 3.0 s later if there were no air resistance?
The gravitational potential energy of two masses at a distance 2.0 m apart is - 8.0 J. What external work must be done on this system to separate the masses to a distance of 4.0 m?
How does a moving coil galvanometer operate?