Related InterviewSolutions

• The question has statement - 1 and statement - 2 Of the four choices given after the statements , choose the one that best describes the two statements statement - 1 : Sky wave signals are used for long distance radio communication . These signals are in generel , less stable then ground wave signals statement - 2 : The state of inosphere varies from to hour day and season to season .A. Statement-1 is true, Statement-2 is falseB. Statement-1 is true, Statement-2 is true and Statement -2 is the correct explanation of Statement-1C. Statement-1 is true , Statement -2 is true and Statement-2 is not the correct explanation of Statement-1D. Statement-1 is false but Statement-2 is true.
• If the lattice constant of this semiconductor is decreased, then which of the following is correct ? .A. `E_(c)` and `E_(v)` decrease, but `E_(g)` increasesB. All `E_(c) , E_(g) E_(v)` decreaseC. All `E_(c), E_(g) , E_(v)` increaseD. `E_(c)` and `E_(v)` increase, but `E_(g)` decreases
• The main cause of avalence breakdown isA. collision ionisationB. high dopingC. recombination of electron and holesD. none of these
• A cube of germanium is placed between the poles of a magnet and a voltage is applied across opposite faces of the cube as shown in Figure. Magnetic field is directed vertical downward in the plane of the paper : What effect will occur at the surface of the cube ? A. The top surface of cube will become negative chargedB. The front surface of the cube will become positively chargedC. The front surface of the cube will become negative chargedD. Both top and front surface of cube will become positively charged
• Statement -1: When lightning strikes a metal pipe, the pipe tends to contact. Statement-2: Parallel current attract each other.A. Statement-1 is true, statement-2 is true and statement-2 is correct explanation for statement-1.B. Statement-1 is true, statement-2 is true and statement-2 is NOT the correct explanation for statement-1.C. Statement-1 is true, statement-2 is false.D. Statement -1 is false, statement -2 is true.
• A hollow copper sphere & a hollow copper cube of same surface area & negligible thickness , are filled with warm water of same temperature and placed in an enclosure of constant temperature a few degrees below that of the bodies. Then in the beginning:-A. the rate of energy lost by the sphere is greater than that by the cubeB. the rate of energy lost by the two are equalC. the rate of energy lost by the sphere is less than that by the cubeD. the rate of fall of temperature for sphere is less than that for the cube.
• A gas is filled in an organ pipe and it is sounded in fundamental mode. Choose the correct statement(s) (T=constant)A. If gas is changed from `H_(2) to O_(2)`, the resonant frequency will increaseB. If gas is changed from `O_(2) to N_(2)`, the resonant frequency will increaseC. if gas is changed from `N_(2) to He`, the resonant frequency will decreaseD. If gas is changed from `He to CH_(4)`,the resonant frequency will decrease
• There is a cubical cavity inside a conducting sphere of radius R. A positive point charge Q is placed at the centre of the cube and another positive charge q is placed at a distance `1(gtR)` from the centre of the sphere. The sphere is earthed Net charge on the outer surface of conducting sphere isA. zeroB. positiveC. negativeD. can not be determined.
• In the given circuit `V_(O_(1))&V_(O_(2))` areA. `11.3` V & `0.3` VB. `0.3` V & `11.3` VC. `11.3` V & `11.3` VD. `0.3` V & `0.3` V
• Which is the correct diagram of a half- wave reactifier?A. B. C. D.