25W
50W
120W
125W
Correct answer is A
P = IVcos\(\theta\)
= 5 x 10 x cos60
= 25W
What is the total electrical energy consumed by using an electric cooker rated 1000W for 5 hrs?
5.3 x 103J
6.5 X 103J
1.8 X 107J
2.3 X 107J
Correct answer is C
Energy = power x time
= 1000 x 5 x 3600
= 1.8 X 107J
5.00 x 10-5C
2.50 x 10-3C
1.25 x 10-3C
1.00 x 10-2C
Correct answer is D
For series, C = \(\frac{50 \times\ 50}{50 + 50}\)
C= 25\(\mu\)F
Q = CV
Q = 25 x 100 x 10-3
Q = 2.5 x 10-3C
20cm
40cm
60cm
80cm
Correct answer is B
Let the point be x
\(\frac{2}{x}\) = \(\frac{3}{100 - x}\)
making x subject of formula,
2(100 - x) = 3x
200 - 2x = 3x
200 = 3x + 2x
200 = 5x
divide both side by 5
x = 40cm
4.0 x 102 v
4.0 x 104 v
8.0 x 102 v
8.0 x 10-2 v
Correct answer is C
V = \(\frac{W}{Q}\)
V = \(\frac{8 \times\ 10^{-2}}{100 \times\ 10^{-6}}\)
V = 8.0 x 10\(^2\) v