The effective resistance between points P and Q of the electrical circuit shown in the figure is

(1) $2Rr/\left(R+r\right)$

(2) $8R\text{\hspace{0.17em}}\left(R+r\right)/\left(3R+r\right)$

(3) $2r+4R$

(4) $5R/2\text{\hspace{0.17em}\hspace{0.17em}}+\text{\hspace{0.17em}}2r$

Concept Questions :-

Combination of resistors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In the circuit element given here, if the potential at point B, VB = 0, then the potentials of A and D are given as

(1) ${V}_{A}=-1.5\text{\hspace{0.17em}}V,\text{\hspace{0.17em}}{V}_{D}=+2\text{\hspace{0.17em}}V$

(2) ${V}_{A}=+1.5\text{\hspace{0.17em}}V,\text{\hspace{0.17em}}{V}_{D}=+2\text{\hspace{0.17em}}V$

(3) ${V}_{A}=+1.5\text{\hspace{0.17em}}V,\text{\hspace{0.17em}}{V}_{D}=+0.5\text{\hspace{0.17em}}V$

(4) ${V}_{A}=+1.5\text{\hspace{0.17em}}V,\text{\hspace{0.17em}}{V}_{D}=-0.5\text{\hspace{0.17em}}V$

Concept Questions :-

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

Difficulty Level:

The current in a conductor varies with time t as $I=2t+3{t}^{2}$ where I is in ampere and t in seconds. The electric charge flowing through a section of the conductor during t = 2 sec to t = 3 sec is :

(1) 10 C

(2) 24 C

(3) 33 C

(4) 44 C

Concept Questions :-

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

Difficulty Level:

A group of N cells whose emf varies directly with the internal resistance as per the equation EN = 1.5 rN are connected as shown in the figure below. The current I in the circuit is

1. 0.51 A

2. 5.1 A

3. 0.15 A

4. 1.5 A

Concept Questions :-

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

Difficulty Level:

In the shown arrangement of the experiment of the meter bridge if AC corresponding to null deflection of galvanometer is x, what would be its value if the radius of the wire AB is doubled

(1) x

(2) x/4

(3) 4x

(4) 2x

Concept Questions :-

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

Difficulty Level:

Seven resistances are connected as shown in the figure. The equivalent resistance between A and B is

(1) 3 Ω

(2) 4 Ω

(3) 4.5 Ω

(4) 5 Ω

Concept Questions :-

Combination of resistors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A battery of internal resistance 4Ω is connected to the network of resistances as shown. In order to give the maximum power to the network, the value of R (in Ω) should be :

(1) 4/9

(2) 8/9

(3) 2

(4) 18

Concept Questions :-

Combination of resistors
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In the circuit shown here, the readings of the ammeter and voltmeter are [Kerala PMT 2002]

(1) 6 A, 60 V

(2) 0.6 A, 6 V

(3) 6/11 A, 60/11 V

(4) 11/6 A, 11/60 V

Concept Questions :-

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

Difficulty Level:

Length of a hollow tube is 5m, it’s outer diameter is 10 cm and thickness of it’s wall is 5 mm. If the resistivity of the material of the tube is 1.7 × 10–8 Ω×m then the resistance of the tube will be :

(1) 5.6 × 10–5 Ω

(2) 2 × 10–5 Ω

(3) 4 × 10–5 Ω

(4) None of these

Concept Questions :-

Derivation of Ohm's law
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A wire of resistor R is bent into a circular ring of radius r. Equivalent resistance between two points X and Y on its circumference, when angle XOY is α, can be given by

(1) $\frac{R\alpha }{4{\pi }^{2}}\left(2\pi -\alpha \right)$

(2) $\frac{R}{2\pi }\left(2\pi -\alpha \right)$

(3) R (2πα)

(4) $\frac{4\pi }{R\alpha }\left(2\pi -\alpha \right)$

Concept Questions :-

Combination of resistors