When water is heated from 0° C to 4 ° C, its volume decreases. Density = Mass/Volume
And density of water is maximum at 4 ° C.

Correct Option: B

When water is heated from 0° C to 4 ° C, its volume decreases. Density = Mass/Volume
And density of water is maximum at 4 ° C.

Heat given/taken by the substance is equal to the latent heat of fusion or vaporization of the substance. That is why the temperature of the substance remains the same during the change of the state.

Correct Option: C

Heat given/taken by the substance is equal to the latent heat of fusion or vaporization of the substance. That is why the temperature of the substance remains the same during the change of the state.

Thermostat is a device which automatically regulates the temperature of a system. As the word suggests.
Thermostat = Thermo + stat i.e., keeping temperature (Thermo) Constant (static)

Correct Option: C

Thermostat is a device which automatically regulates the temperature of a system. As the word suggests.
Thermostat = Thermo + stat i.e., keeping temperature (Thermo) Constant (static)

The safest temperature food keeping food fresh in a refrigerator is 4°C. At this temperature density of water is maximum.

Correct Option: A

The safest temperature food keeping food fresh in a refrigerator is 4°C. At this temperature density of water is maximum.

If the doors of a refrigerator are left open for a few hours, the room temperature will increases. It is because system releases heat to the surroundings.

Correct Option: B

If the doors of a refrigerator are left open for a few hours, the room temperature will increases. It is because system releases heat to the surroundings.