Question 1

Refer to the first circuit diagram (with three resistors of $$R$$ ohms each). What is the equivalent resistance between points A and B?

Accepted Answer

$$\frac{2}{3}R$$

Question 2

In the second circuit diagram, if $$R_1 = 10$$\ \Omega$$, R_2$ = R_3$ = 5\ \Omega$$, $$E = 5\ V$$, and $$r = 0$$, what is the current through branch $$bg$$?

Accepted Answer

$$0.5\ 	ext{A}$$

Question 3

In the third diagram (potentiometer setup), what is the principle behind the working of the potentiometer?

Accepted Answer

It compares the emf of two cells without drawing current from them.

Question 4

Refer to the fourth diagram (resistance vs temperature for Hg). What happens to the resistance of mercury near $$T_C$$?

Accepted Answer

It decreases to zero.

Question 5

In the fifth diagram (current vs voltage for a semiconductor), which region shows negative resistance?

Accepted Answer

Region C

Question 6

In the sixth diagram (potentiometer with balancing length $$l$$), if the resistance $$R_{AB} = 50\ \Omega$$ and the total length is $$10\ 	ext{m}$$, what is the potential gradient along the wire if the driver cell is $$5\ V$$?

Accepted Answer

$$0.05\ 	ext{V/m}$$

Question 7

In the seventh diagram, what is the total current supplied by the $$8\ V$$ battery if all resistors are ideal and the $$3\ V$$ battery is reversed?

Accepted Answer

$$0.2\ 	ext{A}$$

Question 8

In the eighth diagram, what is the reading of the ammeter if the internal resistance of the battery is $$2\ \Omega$$ and the external resistor is $$4\ \Omega$$ with a $$12\ V$$ battery?

Accepted Answer

$$2\ 	ext{A}$$

Question 9

In the ninth diagram, two cells of $$10\ V$$ and $$200\ V$$ are connected in parallel with a $$38\ \Omega$$ resistor. What is the direction of current through the $$10\ V$$ cell?

Accepted Answer

From negative to positive terminal

Question 10

In the tenth diagram (V-I graph for a metallic wire at two temperatures $$T_1$$ and $$T_2$$), which temperature is higher?

Accepted Answer

$$T_2$$

Question 11

In the eleventh diagram, as the variable resistor $$R$$ increases, what happens to the terminal voltage $$V$$ across the cell?

Accepted Answer

It increases and approaches the emf $$\varepsilon$$

Question 12

In the twelfth diagram (meter bridge), if the balance point is at $$l_1$$ with resistances $$R$$ and $$S$$, and when an unknown resistance $$X is $$connected in parallel with $$S$$ the balance point shifts to $$l_2$$, what is the expression for $$X$$?

Accepted Answer

$$X = S \left( \frac{l_1$ - l_2$}{l_2$} \right)$$

Question 13

In the thirteenth diagram, if $$R_0 is $$the resistance of the potentiometer wire and $$R is $$the load resistance connected at the midpoint, what is the voltage across $$R$$?

Accepted Answer

$$V \frac{R}{R_0$/2 + R}$$

Question 14

In the fourteenth diagram (current-voltage graph for a semiconductor), what does the region between points B and C represent?

Accepted Answer

Negative resistance region

Question 15

In the fifteenth diagram, if the current through the $$15\ \Omega$$ resistor is $$0.2\ 	ext{A}$$, what is the voltage across it?

Accepted Answer

$$3\ V$$

Question 16

In the sixteenth diagram (meter bridge), if $$R = 10\ \Omega$$, $$X = 20\ \Omega$$, and the balance point is at $$l = 40\ 	ext{cm}$$, what is the total length of the wire?

Accepted Answer

$$100\ 	ext{cm}$$

Question 17

In the seventeenth diagram, if $$R_1 = 2$$\ \Omega$$, R_2$ = 3\ \Omega$$, $$R_3 = 4$$\ \Omega$$, R_4$ = 2\ \Omega$$, $$R_5 = 2$$\ \Omega$$, and the battery is 4$$\ V$$, what is the total resistance of the circuit?

Accepted Answer

$$3\ \Omega$$

Question 18

In the eighteenth diagram (meter bridge with $$X in $$parallel with $$S$$), if the balance point shifts from $$l_1 to$$ $$l_2$$, what does this indicate about the value of $$X$$?

Accepted Answer

$$X is $$less than $$S$$

Step-by-Step Guidance for Electric Current and Circuits (Physics with Calculus)

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