Ohms law and resistance DPP-10(ISC)

Express which of the following setups can be used to verify Ohm’s law

• 
• 
• 
• 

When a potential difference is applied across the ends of a linear metallic conductor

• The free electrons are accelerated continuously from the lower potential end to the higher potential end of the conductor

• The free electrons are accelerated continuously from the higher potential end to the lower potential end of the conductor

• The free electrons acquire a constant drift velocity from the lower potential end to the higher potential end of the conductor

• The free electrons are set in motion from their position of rest

The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance

• Length = 50 cm, diameter = 0.5 mm

• Length = 100 cm, diameter = 1 mm

• Length = 200 cm, diameter = 2 mm

• Length = 300 cm, diameter = 3 mm

The current in the adjoining circuit will be

• $\frac{1}{45}ampere$

• $\frac{1}{15}ampere$

• $\frac{1}{10}ampere$

• $\frac{1}{5}ampere$

The reading of the ammeter as per figure shown is

• $\frac{1}{8}A$

• $\frac{3}{4}A$

• $\frac{1}{2}A$

• 2A

A wire has a resistance of 12 ohm. It is bent in the form of equilateral triangle. The effective resistance between any two corners of the triangle is

• 9 ohms

• 12 ohms

• 6 ohms

• 8/3 ohms

Two resistors are connected (a) in series (b) in parallel. The equivalent resistance in the two cases are 9ohm and 2ohm respectively. Then the resistances of the component resistors are

• 2 ohm and 7 ohm

• 3 ohm and 6 ohm

• 3 ohm and 9 ohm

• 5 ohm and 4 ohm

 Resistances of 6 ohm each are connected in the manner shown in adjoining figure. With the current 0.5 ampere as shown in figure, the potential difference  $V_p-V_Q$    is

• 3.6 V

• 6.0 V

• 3.0 V

• 7.2 V

Four resistances are connected in a circuit in the given figure. The electric current flowing through 4 ohm and 6 ohm resistance is respectively

• 2 amp and 4 amp

• 1 amp and 2 amp

• 1 amp and 1 amp

• 2 amp and 2 amp

 Two wires of same metal have the same length but their cross-sections are in the ratio 3:1 . They are joined in series. The resistance of the thicker wire is $10\Omega$   . The total resistance of the combination will be 

•  $40\Omega$  

•  $\frac{40}{3}\Omega$  

•  $\frac{5}{3}\Omega$  

•  $100\Omega$