Please solve both the questions .

​Q7. The current through S when it is closed in the circuit is

       (A) 4.8 A

       (B) 2.4 A

       (C) 1.2 A

       (D) 0.6 A
                 
                              
Q8. A voltmeter has a resistance of 1800 $\mathrm{\Omega }$ is used to measure the potential difference across a 200 $\mathrm{\Omega }$ resistor which is connected to the terminals of a DC power supply having an emf of 50 V and an internal resistance of 20 ​$\mathrm{\Omega }$. Find the percentage decrease in the potential difference across the 200 ​$\mathrm{\Omega }$ resistor as a result of connected the voltmeter across is?

   (A) 1 %                           (B) 5 %                      (C) 10 %                         (D) 25%