# The value of $$R$$ in the given circuit when there is no current in the $$5 ~\Omega$$ resistor is:   1. $$12~\Omega$$ 2. $$9~ \Omega$$ 3. $$3~ \Omega$$ 4. $$2~ \Omega$$

Subtopic:  Wheatstone Bridge |
81%
From NCERT
NEET - 2024
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There are two heaters $$A$$ and $$B.$$ Heater $$A$$ takes time $$t_1$$ to boil a given quantity of water, while $$B$$ takes time $$t_2$$ to boil the same quantity of water across same supply voltage. If the two heaters are connected in series, time taken by this combination to boil the same quantity of water will be:
 1 $$\large\dfrac{t_1t_2}{t_1+t_2}$$ 2 $$t_1+t_2$$ 3 $${\large\dfrac12}(t_1+t_2)$$ 4 $$\large\dfrac{t_1t_2}{2(t_1+t_2)}$$
Subtopic:  Heating Effects of Current |
58%
From NCERT
NEET - 2024
Hints

Arrange the following in the order of their resistance.
 A. ($$0$$ to $$1~\text A$$) ranged ammeter. B. ($$0$$ to $$100~\text {mA}$$) ranged milli-ammeter. C. ($$0$$ to $$500~\mu\text A$$) ranged micro-ammeter. D. ($$0$$ to $$100~\text V$$) ranged voltmeter.

Choose the correct answer from the options given below:
 1 A > B > C > D 2 D > C > B > A 3 D > A > B > C 4 C > B > A > D
Subtopic:  Derivation of Ohm's Law |
54%
From NCERT
NEET - 2024
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The equivalent resistance $$R_{AB}$$ between points $$A$$ and $$B$$ in the given network is:

1. $$1R$$
2. $${\dfrac35}R$$
3. $${\dfrac78}R$$
4. $${\dfrac58}R$$
Subtopic:  Combination of Resistors |
72%
From NCERT
NEET - 2024
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Two heaters $$\mathrm{A}$$ and $$\mathrm{B}$$ have power rating of $$1~\text{kW}$$ and $$2~\text{kW}$$, respectively. Those two are first connected in series and then in parallel to a fixed power source. The ratio of power outputs for these two cases is:
1. $$2:9$$
2. $$1:2$$
3. $$2:3$$
4. $$1:1$$
Subtopic:  Heating Effects of Current |
56%
From NCERT
NEET - 2024
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A wire of length $$'l'$$ and resistance $$100 ~\Omega$$ is divided into $$10$$ equal parts. The first $$5$$ parts are connected in series while the next $$5$$ parts are connected in parallel. The two combinations are again connected in series. The resistance of this final combination is:
 1 $$52~ \Omega$$ 2 $$55~ \Omega$$ 3 $$60 ~\Omega$$ 4 $$26~ \Omega$$
Subtopic:  Combination of Resistors |
65%
From NCERT
NEET - 2024
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The terminal voltage of the battery, whose emf is $$10~\text V$$ and internal resistance  $$1~\Omega,$$ when connected through an external resistance of $$4~\Omega$$ as shown in the figure is:

 1 $$6~\text V$$ 2 $$8~\text V$$ 3 $$10~\text V$$ 4 $$4~\text V$$
Subtopic:  EMF & Terminal Voltage |
64%
From NCERT
NEET - 2024
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A uniform wire of diameter $$d$$ carries a current of $$100~\text{mA}$$ when the mean drift velocity of electrons in the wire is $$v.$$ For a wire of diameter $${\dfrac{d}{2}}$$ of the same material to carry a current of $$200~\text{mA},$$ the mean drift velocity of electrons in the wire is:
 1 $$4v$$ 2 $$8v$$ 3 $$v$$ 4 $$2v$$
Subtopic:  Current & Current Density |
65%
From NCERT
NEET - 2024
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In an electrical circuit, the voltage is measured as $${V}=(200\pm4)$$ volts and the current is measured as $${I}=(20\pm0.2)~\text A.$$ The value of the resistance is:
1. $$(10\pm4.2)~\Omega$$
2. $$(10\pm0.3)~\Omega$$
3. $$(10\pm0.1)~\Omega$$
4. $$(10\pm0.8)~\Omega$$
Subtopic:  Derivation of Ohm's Law |
From NCERT
NEET - 2024
A uniform metal wire of length $$l$$ has $$10~\Omega$$ resistance. Now this wire is stretched to a length $$2l$$  and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is:
 1 $$10~\Omega$$ 2 $$5~\Omega$$ 3 $$40~\Omega$$ 4 $$20~\Omega$$