The figure below shows a 2.0 V potentiometer used for the determination of internal resistance of a 1.5 V cell. The balance point of the cell in open circuit is 76.3 cm. When a resistor of 9.5 Ω is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. Determine the internal resistance of the cell.
(a) 1.7 Ω
(b) 2.7 Ω
(c) 3.7 Ω
(d) 1.1 Ω
(a) 1.7 Ω
(b) 2.7 Ω
(c) 3.7 Ω
(d) 1.1 Ω
(a) 1.7 Ω
A Daniel cell is balanced on 125 cm length of a potentiometer wire. When the cell is short circuited with a 2 Ω resistance, the balancing length obtained is 100 cm. Internal resistance of the cell will be
(a) 1.5 Ω
(b) 0.5 Ω
(c) 1.25 Ω
(d) 4/5 Ω
Distinguish between emf (E) and terminal voltage (V) of a cell having internal resistance r. Draw a plot showing the variation of terminal voltage (V) Vs. the current (I) drawn from the cell. Using this plot, how does one determine the internal resistance of the cell ?
A battery of emf E and internal resistance, r, when connected with an external resistance of 12Ω produces a current of 0.5 A. When connected across a resistance of 25Ω, it produces a current of 0.25 A. Determine
(i) the emf and (ii) the internal resistance of the cell.
A new flashlight cell of emf 1.5 volts gives a current of 15 amps, when connected directly to an ammeter of resistance 0.04 Ω. The internal resistance of cell is
(a) 0.04 Ω
(b) 0.06 Ω
(c) 0.10 Ω
(d) 10 Ω
In meter bridge, the balancing length from left end when standard resistance of 1 Ω is in right gap is found to be 20 cm. The value of unknown resistance is
(a) 0.25 Ω
(b) 0.4 Ω
(c) 0.5 Ω
(d) 4 Ω
The figure shows a plot of terminal voltage ‘V’ versus the current ‘i’ of a given cell. Calculate from the graph
(i) emf of the cell and (ii) internal resistance of the cell.
A battery of emf 10 V and internal resistance 3 ohm is connected to a resistor. If the current in the circuit is 0.5 A, find :
(i) the resistance of the resistor;
(ii) the terminal voltage of the battery.
An electric charge of 425 f μC is removed from a fully charged capacitor of capacitance 8.5μF. Its potential will be lowered by:
(a) 75 V
(b) 100 V
(c) 85 V
(d) 50 V
A deuteron of kinetic energy 50 keV is describing a circular orbits of radius 0.5 m in a plane perpendicular to the magnetic field B . The kinetic energy of the proton that describes a circular orbit of same radius and inside same B is-
(a) 25 kev
(b) 50 kev
(c) 200 kev
(d) 100 keV
In a meter bridge as shown, the balance point is found to be at 39.5 cam from the end A, when the resistor Y is of 12.5 Ω. Determine the balance point of the bridge above if X and Y are interchanged.
(a) 8.2 Ω, 40.6 cm
(b) 8.2 Ω, 60.4 cm
(c) 6.2 Ω, 60.4 cm
(d) 6.2 Ω, 39.6 cm
In Young’s double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement, the new fringe width will be :
i. 0.3 mm
ii. 0.4 mm
iii. 0.53 mm
iv. 0.75 mm
Coherence is a measure of
(A) capability of producing interference by waves
(B) waves being diffracted
(C) waves being reflected
(D) waves being refracted
Select the correct statements from the following
(i) inside a charged or neutral conductor, electrostatic field is zero.
(ii) the electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.
(iii) there is no net charge at any point inside the conductor.
(A) (i) and (ii)
(B) i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii), and (iii)
Two interfering beams have intensities in the ratio of 9:4. Then the ratio of maximum to minimum intensity in the interference pattern is
(A) 25:1
(B) 13:5
(C) 5:1
(D) 3:2