Electric Current and Potential

Q.

Define electric energy, electric power and write their SI units and commercial units.

Q. During the electrolysis of water:

1. Bubbles are formed
2. Colour of the water changes
3. Electrodes are heated up
4. Water evaporates

Q.

Adding common salt to distilled water makes

1. Good conductor

2. Insulator

3. Cannot say

4. All of these

Q. Chemical effects of electric current are observed due to ____.

1. change in temperature
2. change in state of the matter
3. chemical reactions
4. physical changes

Q.

Give the definitions of an electrode. Is it a poor conductor or a good conductor of electricity?

Q. An electric heater consumes 1.1 kW power when 220 V voltage is applied to it. How much current will be flowing through it?

1. 1.1A
2. 2.2A
3. 4A
4. 5A

Q.

Choose the correct relation between I, q and t (I - current, q - charge, t - time).

1. $I=\frac{t}{q}$
2. $I=\frac{I}{t^2}$
3. $I=\frac{q}{t}$
4. $I=q\times t$

Q.

Identify the circuit (figure) in which the electrical components have been properly connected. [1 Mark]
(i) (ii) (iii) (iv)

(a) (i)
(b) (ii)
(c) (iii)
(d) (iv)

Q. An electric oven of 2 kW power rating is operated in a domestic electric circuit that has a current rating of 5A. If the supply voltage is 220V, what result do you expect ? Explain.

Q. What is meant by electric current? Name and define its S.I. unit

Q. Identify the chemical effects of electric current from the following.

1. Change in colour of the solution.
2. Deposition of metal on electrodes.
3. Evaporation of chemicals.
4. Formation of bubbles of gas on the electrodes.

Q. If a charge of $Q$ coulombs flows through a conductor in $t$ seconds, then what is the formula for magnitude of the current ?

Q.

In which direction does current flow in an electric circuit?

Q. What is the current flowing through an appliance marked $240V,40W$?

1. $0.17A$
   
2. $3.00A$
   
3. $6.67A$
   
4. $6.00A$
   

Q. is the amount of work done to move a unit positive charge from one point to another point.

1. Potential difference
2. Resistivity
3. Amplitude
4. Capacitance

Q. The device which can directly measure the electric potential difference between two points is / are:

1. Voltmeter
2. Ammeter
3. Galvanometer
4. Multimeter

Q. Wires are made of materials that are good conductors of electricity.

1. True
2. False

Q. Which one of the following is the unit of electric power/sec?

1. Joule
2. Coulomb
3. Volt/m
4. Watt

Q. Match column I with column II and select the correct answer using the codes given below:
Column I Column II
(A) Electric potential (p) The obstruction offer to the flow of charge
(B) Electric current (q) The electric work done per unit time
(C) Electric power (r) The rate of flow of charges
(D) Resistance (s) The electric work done per unit charge

1. (A) $\to$ s; (B) $\to$ r; (C) $\to$ q; (D) $\to$ p
2. (A) $\to$ p; (B) $\to$ r; (C) $\to$ s; (D) $\to$ q
3. (A) $\to$ q; (B) $\to$ r; (C) $\to$ p; (D) $\to$ s
4. (A) $\to$ s; (B) $\to$ p; (C) $\to$ r; (D) $\to$ q

Q. Copper wires are jacketed inside a layer of rubber. This is because rubber is an insulator.

1. False
2. True

Q.
The bulb in the given electrical circuit does not glow even after the switch is turned ON. Which of the following could be a possible reason for this?

1. Bulb is fused.
2. Solution is non-electrolytic.
3. Connections are faulty.
4. Battery is weak.

Q.

The electric current flows in a conductor due to:

1. The area of the conductor.

2. The weight of the conductor.

3. The potential difference.

4. The temperature of the conductor.