Two sources of equal emf are connected to an external resistance R. The internal resistances of the two sources are R1 and ${R}_{2}\text{\hspace{0.17em}}\left({R}_{2}>{R}_{1}\right)$. If the potential difference across the source having internal resistance R2 is zero, then

(1) $R={R}_{1}{R}_{2}/\left({R}_{1}+{R}_{2}\right)$

(2) $R={R}_{1}{R}_{2}/\left({R}_{2}-{R}_{1}\right)$

(3) $R={R}_{2}×\left({R}_{1}+{R}_{2}\right)/\left({R}_{2}-{R}_{1}\right)$

(4) $R={R}_{2}-{R}_{1}$

Concept Questions :-

Grouping of cells
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The magnitude of i in ampere unit is

(1) 0.1

(2) 0.3

(3) 0.6

(4) None of these

Concept Questions :-

Kirchoff's voltage law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

To draw maximum current from a combination of cells, how should the cells be grouped

(1) Series

(2) Parallel

(3) Mixed

(4) Depends upon the relative values of external and internal resistance

Concept Questions :-

Grouping of cells
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

By ammeter, which of the following can be measured

(1) Electric potential

(2) Potential difference

(3) Current

(4) Resistance

Concept Questions :-

Current and current density
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

For measurement of potential difference, potentiometer is preferred in comparison to voltmeter because

(1) Potentiometer is more sensitive than voltmeter

(2) The resistance of potentiometer is less than voltmeter

(3) Potentiometer is cheaper than voltmeter

(4) Potentiometer does not take current from the circuit

Concept Questions :-

Meter bridge and potentiometer
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The potential gradient along the length of a uniform wire is 10 volt/metre. B and C are the two points at 30 cm and 60 cm point on a meter scale fitted along the wire. The potential difference between B and C will be :

(1) 3 volt

(2) 0.4 volt

(3) 7 volt

(4) 4 volt

Concept Questions :-

Meter bridge and potentiometer
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In Wheatstone's bridge P = 9 ohm, Q = 11 ohm, R = 4 ohm and S = 6 ohm. How much resistance must be put in parallel to the resistance S to balance the bridge

(1) 24 ohm

(2) $\frac{44}{9}$ohm

(3) 26.4 ohm

(4) 18.7 ohm

Concept Questions :-

Wheatstone bridge
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A potentiometer is an ideal device of measuring potential difference because

(1) It uses a sensitive galvanometer

(2) It does not disturb the potential difference it measures

(3) It is an elaborate arrangement

(4) It has a long wire hence heat developed is quickly radiated

Concept Questions :-

Meter bridge and potentiometer
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A battery of 6 volts is connected to the terminals of a three metre long wire of uniform thickness and resistance of the order of 100 Ω. The difference of potential between two points separated by 50cm on the wire will be :

(1) 1 V

(2) 1.5 V

(3) 2 V

(4) 3 V

Concept Questions :-

Kirchoff's voltage law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A potentiometer is used for the comparison of e.m.f. of two cells E1 and E2. For cell E1 the no deflection point is obtained at 20cm and for E2 the no deflection point is obtained at 30cm. The ratio of their e.m.f.'s will be

(1) 2/3

(2) 1/2

(3) 1

(4) 2

Concept Questions :-

Meter bridge and potentiometer