Answer:
Option (b)
Explanation:
let the weight of boat is W. In equilibrium condition, the weight of boat is equal to the buoyant force acting on the boat.
The buoyant force acting on the boat is equal to the weight of water displaced by the boat.
In case of fresh water:
Weight of the boat = weight of fresh water displaced by the boat
W = Volume of fresh water displaced x density of fresh water x g
W = V x 1 x g
W = V x g ....... (1)
In case of salt water:
Let the volume of salt water displaced is V'.
Weight of the boat = weight of salt water displaced by the boat
W = Volume of salt water displaced x density of salt water x g
W = V' x 1.02 x g ..... (2)
Equate equation (1) and equation (2), we get
V x g = V' x 1.02 x g
V' = 0.98 V
Thus, option (b) is true.
Answer:

Explanation:
for the calculation of the electric potential inside a parallel plate capacitor you can use the formula for the electric field inside the capacitor.

where d is the distance between plates and E is the electric field, which is given by:

By replacing you obtain:

where Q is the charge stored by the capacitor and A is the area of the plates.
hence, the answer is Qd/Ae0
Explanation :
A circuit is the representation of the path of the flow of current. The circuit can be either closed or open.
When the switch is off the circuit is closed circuit and when the switch is not connected the circuit is open.
The items that are sufficient to make a circuit are as follows :
- Voltage source like a battery.
- Resistors or electrical equipment like heater, motor etc.
Other components can be ammeter, voltmeter, ac source, variable resistors etc.
It would be the average I guess..300c temperature.Heat flows from higher temp. to lower temp. till the temp. of both the liquids are same.