- (a) presence of electron
- (b) presence of proton
- (c) absence of electron
- (d) absence of proton
Answer:
(c) absence of electron
- (a) creates electric charge
- (b) transfers electric charge
- (c) either (a) or (b)
- (d) neither (a) nor (b)
Answer:
(b) transfers electric charge
Charges are not created; electrons are transferred.
- (a) start; start
- (b) start; end
- (c) start; end
- (d) end; end
Answer:
(b) start; end
- (a) force
- (b) ability
- (c) tendency
- (d) work
Answer:
(d) work
- (a) Joule heating
- (b) Coulomb heating
- (c) Voltage heating
- (d) Ampere heating
Answer:
(a) Joule heating
- (a) electrons
- (b) positive ions
- (c) both (a) and (b)
- (d) neither (a) nor (b)
Answer:
(c) both (a) and (b)
In electrolytes, current is mainly due to movement of ions.
- (a) heating effect
- (b) chemical effect
- (c) flowing effect
- (d) magnetic effect
Answer:
(b) chemical effect
- (a) temperature
- (b) geometry
- (c) nature of material
- (d) all the above
Answer:
(d) all the above
| Quantity | Unit |
|---|---|
| Electric charge | coulomb |
| Potential difference | volt |
| Electric field | newton per coulomb |
| Resistance | ohm |
| Electric current | ampere |
If false, correct the statement.
Answer: True
Answer: False
Correct Statement:
An ammeter is connected in series in an electric circuit.
Answer: False
Correct Statement:
The anode in an electrolyte is positive.
Answer: True
- Electrons move from lower potential to higher potential.
- The direction opposite to electron flow is called conventional current.
- The e.m.f. of a cell is analogous to a water pump in a pipeline.
- Domestic electricity in India is AC with frequency 50 Hz.
Answer:
A bird sitting on a single electric wire does not complete the circuit. Since there is no potential difference across its body, current does not flow through it.
However, if it touches another wire or ground simultaneously, current will flow and it may get electrocuted.
Answer:
No. The potential difference across a solar cell depends on the intensity of sunlight and the connected load. Since sunlight intensity changes, the voltage also changes.
Answer:
No. Electroplating requires direct current (DC).
Using AC continuously changes the direction of current, so metal ions do not deposit properly on the electrode.
Correction made:
Original answer discussed electrical safety instead of directly answering the question.
Answer:
Electrostatic force depends on:
- Magnitude of charges
- Distance between charges
- Nature of medium between them
According to Coulomb’s law:
Answer:
Imaginary lines representing the direction of electric field around a charge are called electric lines of force.
Answer:
Electric field is the region around a charged body where another charge experiences force.
Answer:
Electric current is the rate of flow of electric charge through a conductor.
Where:
- (I) = current
- (Q) = charge
- (t) = time
SI Unit:
Ampere (A)
Answer:
At constant temperature, current flowing through a conductor is directly proportional to the potential difference across it.
Where:
- (V) = voltage
- (I) = current
- (R) = resistance
Answer:
- Electric iron box
- Water heater
Other examples:
- Toaster
- Electric kettle
Answer:
Household appliances are connected in parallel because:
- Each appliance gets same voltage.
- Appliances work independently.
- Failure of one appliance does not affect others.
Answer:
(i) Earthing
Metal body of appliances is connected to ground.
(ii) Trip Switch / Circuit Breaker
Automatically disconnects circuit during overload.
(iii) Fuse
Protects circuit using heating effect of current.
Given:
Comb gets charge:
(a) Which object lost electrons?
- Comb gained electrons.
- Hair lost electrons.
(b) Number of electrons transferred
Charge of one electron:
Using:
Answer:
Given:
Using:
Using Ohm’s law:
Electrical Symbols in Electronic Circuits
Aim:
To identify electrical symbols used in electronic devices.
Observation:
Common symbols observed include:
- Cell
- Battery
- Switch
- Resistor
- Capacitor
- LED
Heating Effect of Electric Current
Aim:
To observe heating effect of electric current.
Observation:
The pointed aluminium foil melts when current passes through it.
Conclusion:
Electrical energy converts into heat energy due to resistance.
This is called:
Joule Heating
Electroplating Using Copper Sulphate
Aim:
To electroplate a carbon rod with copper.
Observation:
Copper gets deposited on carbon rod.
Conclusion:
Current passing through electrolyte causes chemical reaction and metal deposition.
This process is called:
Electroplating
It is caused by the:
Chemical Effect of Electric Current
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