Physics Flashcards
(31 cards)
What is the formula for heat generated in a conductor?
H = I²Rt
Where H is heat, I is current, R is resistance, and t is time.
What is electric power?
Electric power, P = VI = I²R
Where V is potential difference, I is current, and R is resistance.
What is the SI unit of electric power?
Watt (W)
What are other units of electric power?
Kilowatt (kW) and Horsepower (HP)
1 kW = 1000 W, 1 HP = 746 W.
What is electric energy?
Electric energy (W) = VIt = PRt
Where V is potential difference, I is current, R is resistance, and t is time.
What is the SI unit of electric energy?
Joule (J)
Another unit is watt-hour (Wh).
What is kilowatt-hour (kWh)?
1 kWh = 1000 W × 1 hour = 3.6 × 10^6 J
What is the purpose of an electric fuse?
An electric fuse is a safety device used to protect electric circuits from excess current.
What materials are used in an electric fuse?
Tin-lead alloy (63% tin + 37% lead).
What is overloading in electrical terms?
Overloading occurs when a high current flows through a wire beyond its rating.
What is short circuiting?
Short circuiting occurs when the live wire comes in contact with the neutral wire, causing a decrease in resistance and a high current flow.
What factors affect the maximum safe current through a fuse wire?
It depends on the radius (r) of the wire, not its length.
What is the heating effect of current?
The heating effect occurs when current passes through a conductor, especially if the resistance is high.
What is the rating of an electrical appliance?
The values of power and voltage taken together for an electrical appliance is called the rating of the appliance.
Which bulb glows brighter when a 40 W and a 100 W bulb are connected in parallel?
The 100 W bulb will glow brighter than the 40 W bulb.
Which bulb glows brighter when a 40 W and a 100 W bulb are connected in series?
The 40 W bulb will glow brighter than the 100 W bulb.
What happens in a series circuit if any bulb gets fused?
If any bulb gets fused, then others will not glow.
What happens in a parallel circuit if any bulb gets fused?
If any bulb gets fused, the others will continue to glow.
How should switches be connected in relation to the live wire?
All switches should be connected in series with the live wire.
Why do filament bulbs usually get fused when switched ON?
With a rise in temperature, the resistance of the bulb increases and becomes constant in steady state, causing the bulb to glow more brightly initially and may get fused.
What is the phenomenon called when a direct current flows through an acidic or basic solution?
This phenomenon is called electrolysis.
What are the electrodes in electrolysis called?
The positive terminal is called the anode and the negative terminal is called the cathode.
What are cations in electrolysis?
Cations are the ions carrying positive charge and move towards the cathode.
What are anions in electrolysis?
Anions are the ions carrying negative charge and move towards the anode.
