Advertisements
Advertisements
प्रश्न
Two cells of emf’s approximately 5V and 10V are to be accurately compared using a potentiometer of length 400 cm.
पर्याय
The battery that runs the potentiometer should have voltage of 8V.
The battery of potentiometer can have a voltage of 15V and R adjusted so that the potential drop across the wire slightly exceeds 10V.
The first portion of 50 cm of wire itself should have a potential drop of 10V.
Potentiometer is usually used for comparing resistances and not voltages.
उत्तर
The battery of potentiometer can have a voltage of 15V and R adjusted so that the potential drop across the wire slightly exceeds 10V.
Explanation:
The potential drop along the wires of potentiometer should be greater than emfs of cells.
In a potentiometer experiment, the emf of a cell can be measured if the potential drop along the potentiometer wire is more than the emf of the cell to be determined. Here, values of emfs of two cells are given as 5V and 10V, therefore, the potential drop along the potentiometer wire must be more than 10V.
APPEARS IN
संबंधित प्रश्न
Two metallic wires, P1 and P2 of the same material and same length but different cross-sectional areas, A1 and A2 are joined together and connected to a source of emf. Find the ratio of the drift velocities of free electrons in the two wires when they are connected (i) in series, and (ii) in parallel.
A wheel with 8 metallic spokes each 50 cm long is rotated with a speed of 120 rev/min in a plane normal to the horizontal component of the Earth’s magnetic field. The Earth’s magnetic field at the place is 0.4 G and the angle of dip is 60°. Calculate the emf induced between the axle and the rim of the wheel. How will the value of emf be affected if the number of spokes were increased?
Answer the following question.
Two bulbs are rated (P1, V) and (P2, V). If they are connected (i) in series and (ii) in parallel across a supply V, find the power dissipated in the two combinations in terms of P1 and P2.
Give reason/short answer.
In the given circuit diagram two resistors are connected to a 5V supply.
Calculate potential difference across the 8Ω resistor.
Give reason/short answer.
In the given circuit diagram two resistors are connected to a 5V supply.
A third resistor is now connected in parallel with 6Ω resistor. Will the potential difference across the 8Ω resistor the larger, smaller, or the same as before? Explain the reason for your answer.
Two cells of 1.25 V and 0.75 V are connected in series with anode of one connected to anode of the other. The effective voltage will be ______.
Two metal wires of identical dimensions are connected in parallel. If σ1 and σ2 are the conductivities of the metal wires respectively, the effective conductivity of the combination is
When cells are connected in parallel, then ______
Two cells of emf E1 and E2 and internal resistances r1 and r2 are connected in parallel, with their terminals of the same polarity connected together. Obtain an expression for the equivalent emf of the combination.
A 60 Ω resistor, a 1.0 H inductor and a 4 μF capacitor are connected in series to an ac supply generating an emf e = 300 sin (500t) V. Calculate:
- impedance of the circuit.
- peak value of the current flowing through the circuit.
- phase difference between the current and the supply voltage.
