Correct Answer: D. halved

Correct Answer: B. orange and indigo

Correct Answer: D. 30.75cm³

Explanation

\(V_2 = \frac{P_1V_1T_2}{P_2T_1} = \frac{9.52 \times 10^4 \times 40 \times 273}{1.034 \times 10^5 \times 327}\)

= 30.75cm³

Correct Answer: D. 20cm

Explanation

M = \(\frac{v}{u}\)

v = mu = 4 x 25 = 100m

\(\frac{1}{v} + \frac{1}{u} = \frac{1}{f}\)

\(\frac{1}{100} + \frac{1}{25} = \frac{1}{f}\)

f = 20cm

Explanation

(a) Electrolyte is a substance in liquid or molten state which conducts electricity and undergoes decomposition e.g. metallic salts, acids and alkalis.

(b) M \(\alpha\) Q

M = kQ. Mass m is proportional to charge Q where K is a constant of proportionality.

Correct Answer: C. 1000Hz

Explanation

V = \(\frac{s}{t} = \frac{900}{3} = 300\)m\s

f = \(\frac{v}{\pi} = \frac{300}{0.30}\)

= 1000Hz

Explanation

(a) Surface tension is the property of a liquid which makes its surface behave as though covered by an elastic skin.

(b) Surface tension can be reduce by;

(i) Addition of impurities e.g. soap, oil, alcohol etc.

(ii) Heating the liquid.

Explanation

Any image that can be formed on a screen are called real image. Such images are formed by light rays emanating from the object, when reflected and/or refracted by devices such as lenses and mirrors converge at some specific point. In contrast there are other images which are formed by the rays of light reaching the observer appearing to converge at some point. This happens when the rays reaching the observer are diverging and when the line of these rays are projected backward. Such images, which cannot be formed on a screen, are called virtual image.

Correct Answer: D. Lenz's law

Explanation

Lenz's law, in electromagnetism, statement that an induced electric current flows in a direction such that the current opposes the change that induced it.

Correct Answer: C. with which work can be done easily