When the length and area of cross-section both are doubled, then its resistance :
(1) Will become half
(2) Will be doubled
(3) Will remain the same
(4) Will become four times
1. | proportional to \(T\). | 2. | proportional to\(\sqrt{T} \) |
3. | zero. | 4. | finite but independent of temperature. |
An electric wire of length ‘I’ and area of cross-section a has a resistance R ohms. Another wire of the same material having the same length and area of cross-section 4a has a resistance of :
(1) 4R
(2) R/4
(3) R/16
(4) 16R
A wire of radius r has resistance R. If it is stretched to a radius of , its resistance becomes
(1)
(2)
(3)
(4)
Express which of the following setups can be used to verify Ohm’s law
(1) | |
(2) | |
(3) | |
(4) |
What is the resistance of a carbon resistance which has bands of colours brown, black and brown
(1) 100 Ω
(2) 1000 Ω
(3) 10 Ω
(4) 1 Ω
The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance :
(1) Length = 50 cm, diameter = 0.5 mm
(2) Length = 100 cm, diameter = 1 mm
(3) Length = 200 cm, diameter = 2 mm
(4) Length = 300 cm, diameter = 3 mm
The current in the adjoining circuit will be
(1)
(2)
(3)
(4)
The reading of the ammeter as per figure shown is
(1)
(2)
(3)
(4) 2 A
A current of 2 A flows in a system of conductors as shown. The potential difference will be
(1) +2 V
(2) +1 V
(3) –1 V
(4) –2 V