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
Four resistances are connected in a circuit in the given figure. The electric current flowing through 4 ohm and 6 ohm resistance is respectively
(1) 2 amp and 4 amp
(2) 1 amp and 2 amp
(3) 1 amp and 1 amp
(4) 2 amp and 2 amp
In the given figure, when key K is opened, the reading of the ammeter A will be
(1) 50 A
(2) 2 A
(3) 0.5 A
(4)
Three equal resistances each of value R are joined as shown in the figure. The equivalent resistance between M and N is
(1) R
(2) 2R
(3)
(4)