You are given resistance wire of length 50 cm and a battery of negligible resistance. In which of the following cases is the largest amount of heat generated?

• When the wire is connected to the battery directly

• When the wire is divided into two parts and both the parts are connected to the battery in parallel.

• When the wire is divided into four parts and all the four parts are connected to the battery in parallel.

• When only half of the wire is connected to the battery

When a voltmeter connected across the terminals of cell, measures 5 V and an ammeter connected measures 10 A. A resistance of 2 Ω is connected across the terminal of the cell. The current flowing through this resistance is

• 7.5amp

• 5.0amp

• 2.5amp

• 2.0amp

In a neon discharge tube 2.9 x 10 Ne¹⁸ ions move to be the right per second while 1.2 x 10⁸ electron move to the left per second electric charge is 1.6 x 10^-19C. The current in discharge tube is

• 0.66A towards left

• 0.66 A towards left

• 1A towards right

• Zero

Two equal resistances R are joined with voltage source V in (i)series (ii)parallel, the ratio of electrical power consumed in two cases will be

• 1:4

• 4:1

• 2:1

• 1:2

When a resistance of α Ω is connected at the ends of a battery, its potential difference decreases from 40 V to 30V. The internal resistance of the battery is

• 3Ω

• 6Ω

• 1.5Ω

• 4Ω

46.

The equivalent resistance and potential difference between A and B for the circuit              

respectively are

• 4Ω, 8V

• 8Ω, 4V

• 2Ω, 2V

• 16Ω, 2V

A wire of resistance R is divided in equal parts, then these parts are joined in parallel, the equivalent resistance of the combination will be

• nR

• $\frac{\mathrm{R}}{\mathrm{n}}$

• $\frac{\mathrm{n}}{\mathrm{R}}$

• $\frac{\mathrm{R}}{{\mathrm{n}}^2}$

The potential difference between point A and B is

• $\frac{20}{7 } \mathrm{V}$

• $\frac{40}{7}\mathrm{V}$

• $\frac{10}{7}\mathrm{V}$

• zero

When a certain current is passed in the circuit as shown in figure, 10 kcal of heat is produced in 5 Ω resistance. How much heat is produced in 4 Ω resistance?

• 4 kcal

• 2 kcal

• 5 kcal

• 3 kcal

In the given circuit, what will be the equivalent resistance between the points A and B ?

• 10 / 3 Ω

• 20 / 3 Ω

• 10 / 5 Ω

• 5 Ω