In the circuit grven E =6.0 volt, R₁ = 100 Ω, R₂ = R₃ = 50 Ω, R₄ = 75 Ω. The equivalent resistance of the circurt, in ohms, is

• 11.875

• 26.31

• 118.75

• None of these

Two resistances are connected in two gaps of a metre bridge. The balance point is 20 cm from the zero end. A resistance of 15 ohms is connected in series with the smaller of the two. The null point shifts to 40 cm. The value of the smaller resistance in ohms is

• 3

• 6

• 9

• 12

143.

If the potential difference across the internal resistancer is equal to the emf E of the battery, then

             

• R = r₁ + r₂

• $\mathrm{R} = \frac{{\mathrm{r}}_1}{{\mathrm{r}}_2}$

• R = r₁ − r₂

• $\mathrm{R} = \frac{{\mathrm{r}}_2}{{\mathrm{r}}_1}$

By using only two resistance coils-singly, in senes or in parallel one should be able to obtain resistances of 3, 4, 12 and 16 ohms. The separate resistances of the coil are

• 3 and 4

• 4 and 12

• 12 and 16

• 16 and 3

In the given circuit, the voltmeter records 5 volts. The resistance of the voltmeter in ohms is

• 200

• 100

• 10

• 50

When a body falls in air, the resistance of air depends to a great extent on the shape of the body. 3 different shapes are given. Identify the combination of air resistances which truly represents the physical situation. (The cross-sectional areas are the same).

1. Disc                2. Ball           3. Cigar shaped

• 1 < 2 < 3

• 2 < 3 < 1

• 3 < 2 < 1

• 3 < 1 < 2

The magnitude of I m ampere is

• 0.1

• 0.3

• 0.6

• none of these

A battery of emf 10 V and internal resistance 3 Ω is connected to a resistor. The current in the circuit is 0.5 A. The terminal voltage of the battery when the circuit is closed is

• 10 V

• 0 V

• 1.5 V

• 8.5 V

The electron dirft speed is small and the charge of the electron is also small but still, we obtain large current in a conductor. This is due to

• the conducting property of the conductor

• the resistance of the conductor is small

• the electron number density of the conductor is small

• the electron number density of the conductor is enormous

In the circuit shown, the value of I in ampere is

• 1

• 0.60

• 0.4

• 1.5