Multiple Choice QuestionsA cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short-circuited through a resistance of 10 Ω. Its internal resistance is
1.0 Ω
0.5 Ω
2.0 Ω
2.0 Ω
A.
1.0 Ω
This is a problem is a base on the application of potentiometer in which we find the internal resistance of a cell.
In potentiometer experiment in which we find internal resistance of a cell, let E be the emf of the cell and V the terminal potential differences, then
E/V = l1/l2
where l1 and l2 are the length of potentiometer wire with and without short-circuited through a resistance
The velocity of electromagnetic radiation in a medium of permittivity 
and permeability 
is given by
A long solenoid has 500 turns. When a current of 2 A is passed through it, the resulting magnetic flux linked with each turn of the solenoid is 4 x 10-3 Wb. The self -inductance of the solenoid is
2.5 H
2.0 H
1.0 H
1.0 H
In an AC circuit, the emf (e) and the current (i) at any instant are given respectively by
e = E0 sin ωt
i = Io sin (ωt -Φ)
The average power in the circuit over one cycle of AC is
In the circuit shown, the current through the 4 Ω resistor is 1 A when the points P and M are connected to a DC voltage source. The potential difference between the point M and N is 
1.5 V
1.0 V
0.5 V
0.5 V
A circular disc of radius 0.2 m is placed in a uniform magnetic field of induction in
such a way that its axis makes an angle of 60o with.
The magnetic flux linked with the disc is
0.02 Wb
0.06 Wb
0.05 Wb
0.05 Wb
Curie temperature is the temperature above which
ferromagnetic material becomes paramagnetic material
paramagnetic material becomes diamagnetic material
paramagnetic material becomes ferromagnetic material
paramagnetic material becomes ferromagnetic material
A galvanometer of resistance 50 Ω is connected to a battery of 3 V along with a resistance of 2950 Ω in series. A full-scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
5050 Ω
5550 Ω
6050 Ω
6050 Ω
The work function of a surface of a photosensitive material is 6.2 eV. The wavelength of the incident radiation for which the stopping potential is 5 V lies in the
ultraviolet region
visible region
infrared region
infrared region
The ground state energy of hydrogen atom is -13.6 eV. When its electron is in the first excited state, its excitation energy is
3.4 eV
6.8 eV
10.2 eV
zero
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