Answer:
There is an error in "String s=s1-s2 ";
Explanation:
In java programming, we can subtract subtract two strings variable with "-" operator.Java programming does not support an overload of the '-' operator.In java, we can use only "+" operator to append two strings variable.There is no such method to subtract strings in java.Therefore in the given code String s=s1-s2 will give an "bad operand type" error because we can not subtract one string variable from the second string variable.
Answer:
C. 14.4 kwhr.
Explanation:
To calculate the energy used by appliance first calculate the power. The formulae for calculating power(<em>P</em>) is
, where V stands for voltage and I stands for current.
In the given problem, V = 240 volts and I = 15 amp. Therefore,

Now, formulae for calculating energy used i.e. work(W) is
, where <em>t</em> is the time.
In the given question time is 4 hr. Therefore energy used will be,
Energy used (W) =
.
<em>=</em><em> </em><em>Option</em><em> </em><em>b</em><em> </em><em>Minicomputer ..........</em>
Yeh it’s becoz they work with hardware that’s why
I believe its A as the image provided says plain message