Acircuit consists of a battery and two resistors connected in parallel. if the resistance in both resistors is doubled, and the current is kept constant, how does the voltage change?

a) the voltage is quartered
b) the voltage is halved
c) the voltage remains the same
d) the voltage is doubled

Asmall electric heater, immersed in 80g of water in a calorimeter of 40j/k raises the temperature from 10.5 degree celsius to 25 degree celsius in 12 minutes. using the same apparatus with 50g of oil instead of water, it is found that the temperature of oil rises from 7 degree celsius to 27 degree celsius in 10 minutes. find specific heat capacity of the oil.