# Voltage, Current and Resistance – Exercise – 1

» Exercise – 1

1. Materials with lots of free electrons are called :

(a) conductors
(b) insulators
(c) semiconductors
(d) filters

Explanation
Explanation :

Conductors have lots of free electrons.

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2. The unit of electrical charge is the ________.

(a) coulomb
(b) joule
(c) volt
(d) watt

Explanation
Explanation :

Unit of Charge is Coulomb,
Unit of Energy is Joule,
Unit of Voltage is Volt,
Unit of Power is Watt.

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3. Current flows in a circuit when ________.

(a) a switch is opened
(b) a switch is closed
(c) the switch is either open or closed
(d) there is no voltage

Explanation
Explanation :

When switch is opened, circuit is open and current does not flow.
When switch is closed, circuit is closed and current flows in the closed circuit.

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4. The minimum resistance value for a blue, gray, red, silver resistor is ________.

(a) 612 Ω
(b) 6,120 Ω
(c) 6,800 Ω
(d) 6,460 Ω

Explanation
Explanation :

Because of 10% tolerance (last color silver), this resistance may vary 10% of 6800 Ω.
Minimum resistance value = 6800 – 680 = 6120 Ω,
Maximum resistance value = 6800 + 680 = 7480 Ω.

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5. The maximum resistance value for a brown, red, yellow, gold resistor is ________.

(a) 126,000 Ω
(b) 126,600 Ω
(c) 114,000 Ω
(d) 132,000 Ω

Explanation
Explanation :

Because of 5% tolerance (last color gold), this resistance may vary 5% of 1,20,000 Ω.
Minimum resistance value = 1,20,000 – 6,000 = 1,14,000 Ω,
Maximum resistance value = 1,20,000 + 6,000 = 1,26,000 Ω.

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