Class 12-science H C VERMA Solutions Physics Chapter 11 - Thermal and Chemical Effect of Electric Current
Thermal and Chemical Effect of Electric Current Exercise 218
Solution 1
Heat=
Solution 2
Heat produced by coil=heat to increase temperature of coil
min
Solution 3
Now, P=1000W
Thermal and Chemical Effect of Electric Current Exercise 219
Solution 4
(a)
(b)
m
(c) Number of turns=
Solution 5
Resistance of the bulb
Resistance of copper wire
Total resistance of copper wire(both side connecting wire) =
The effective resistance
The current supplied by the power station
Power supplied/consumed by both side connecting wire
mW
Solution 6
Power=
(a)
W
(b)
W
Solution 7
Resistance of the bulb
For minimum power, voltage should be minimum
Power, W
For maximum power, voltage should be maximum
W
Solution 8
Resistance of the bulb
Let maximum voltage bulb can withstand
volt
Solution 9
Power supplied by the heater=1000W
Power consumed by water=W
minutes
Solution 10
(a) volume of water boiled=cc
Mass of water boiled=
Kg
Heat required for boiling water
J
We know
1000 watt-hour=
cost of boiling 4 cups of water=
(b) If room temperature drops to
Heat required,
J
cost of boiling 4 cups of water=
Solution 11
Resistance of the bulb,
Case 1: When 220V supply is used.
Excess power=100-40=60W
Power converted into light=W
Case 2: When 200V supply is used.
Power consumed by bulb=W
Excess power=82.64-40=42.64W
Power converted into light=W
Now, percentage drop in intensity of light=
Solution 12
Equivalent resistance of the circuit
Current through battery
A
6 and 2 resistance are in parallel combination so current will be distributed in inverse ratio of resistance i.e., in ratio of 1:3.
Current in 2 resistance=A
(a) Heat generated by 2 resistance= heat taken by water and calorimeter
(b) Equivalent resistance of the circuit
Current in 2 resistance
I=2A
Heat generated by 2 resistance=heat taken by water and calorimeter
Solution 13
Emf;
V
Solution 14
Difference in temperature ;
Emf
V
Solution 15
Here,
Thus, the neutral temperature
So, inversion temperature
Solution 16
One equivalent mass of the substance requires 96500 coulombs.
(a) For a monovalent material
Equivalent mass=molecular mass
So, atoms require 96500C
1 atom requires=
(b) For a divalent material
Equivalent mass=
So, atoms require 96500C
1 atom requires=
Solution 17
Since Ag is monoatomic.
Equivalent mass of silver=molecular mass
gm
The ECE of silver
Using,
gm
Solution 18
A
Solution 19
Mass of 1 liter hydrogen, gm
Now,
Minutes.
Solution 20
(a) For the trivalent metal salt
Now,
Atomic weight=
(b)
gm
Solution 21
A
Surface area,
Thickness, t=0.1mm=cm
Volume of Ag deposited= for one side
For both sides, Mass of Ag=gm
Using,
minutes
Solution 22
gm
sec
Now,
A
Heat developed in the 20 resistor
Solution 23
Terminal potential energy, TPD=10V
Emf=12V
We know that, while discharging
A
Using,
gm
Solution 24
Surface area
Thickness
Volume of Ag
Mass of Ag=densityvolume
kg
Using,
C
Energy spent by cell= work done by the cell
kJ
When this energy is used to heat 100gm of water, rise in temperature.