Assertion (A): In a meter bridge experiment null point for an unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by increasing the value of the standard resistance.
Reason (R): Resistance of metal increases with an increase in temperature.

1. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

2. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.

3. If Assertion is true but Reason is false.

4. If both Assertion and Reason are false.

Concept Questions :-

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

Difficulty Level:

A circuit contains an ammeter, a battery of 30 V, and a resistance 40.8 $\Omega$ all connected in series. If the ammeter has the coil of resistance 480 $\Omega$ and a shunt of 20 $\Omega$, then reading in the ammeter will be:

1. 0.5 A

2. 0.02 A

3. 2 A

4. 1 A

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

In the circuit shown, the current through the 4 $\Omega$resistor is 1 A when the points P and M are connected to a DC voltage source. The potential difference  between the points M and N is

1. 1.5 V

2. 1.0 V

3. 0.5 V

4. 3.2 V

Concept Questions :-

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

Difficulty Level:

A cell can be balanced against 110cm and 100 cm of potentiometer wire, respectively with and without being short-circuited through a resistance of . Its internal resistance is

(a) 1.0 $\Omega$

(b) 0.5 $\Omega$

(c) 2.0 $\Omega$

(d) zero

Concept Questions :-

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

Difficulty Level:

An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature ${20}^{°}$C? The temperature of boiling water is ${100}^{°}$C

(a) 6.3 min

(b) 8.4 min

(c) 12.6 min

(d) 4.2 min

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A wire of a certain material is streched slowly by ten per cent. Its new resistance and specific resistance become respectively

(a) 1.2 times, 1.1 times

(b) 1.21 times,same

(c) both remain the same

(d) 1.1 times, 1.1 times

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A current of 3A flows through the 2$\Omega$ resistor shown in the circuit. The power dissipated in the $5\Omega$ resistor is

(a) 4 W                                              (b) 2 W

(c) 1 W                                              (d) 5 W

High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

See the electrical circuit shown in this figure. Which of the following equation is a correct equation for it?

1. ${\epsilon }_{1}-\left({i}_{1}+{i}_{2}\right)R-{i}_{1}{r}_{1}=0$

2. ${\epsilon }_{2}-{i}_{2}{r}_{2}-{\epsilon }_{1}-{i}_{1}{r}_{1}=0$

3. $-{\epsilon }_{2}-\left({i}_{1}+{i}_{2}\right)R+{i}_{2}{r}_{2}=0$

4. ${\epsilon }_{1}-\left({i}_{1}+{i}_{2}\right)R+{i}_{1}{r}_{1}=0$

Concept Questions :-

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

Difficulty Level:

A student measures the terminal potential difference (V) of a cell (of emf $\epsilon$ and internal resistance r) as a function of the current (I) flowing through it. The slope and intercept of the graph between V and I, then respectively, equal :

(a)                                (b)

(c)                                (d)

Concept Questions :-

Emf and terminal voltage
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A wire of resistance  is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points, A and B as shown in the figure, is :

(a)                                                (b)

(c)                                                   (d)

Concept Questions :-

Combination of resistors