Solve for x the quadratic equation x² - 4x - 8 = 0. Give your answer correct to three significant figures.

If (k –3), (2k + 1) and (4k + 3) are three consecutive terms of an A.P,  find the value of k

Write the balanced chemical equation for the laboratory preparation of hydrogen chloride gas.

Cutting of trees should be discouraged.

Give biological reason.

The horrors of the two World Wars, led to the formation of the United Nations Organisation, while the formation of the Non-Aligned Movement followed later. In this context, Explain any three...

Addition of ethyl alcohol to acetic acid in the presence of concentrated Sulphuric acid.

1. What are isobars?
2. Give one example of isobars.

The ratio of amplitude of two waves is 3 : 4. What is the ratio of their:

1. loudness?
2. frequencies?

How is the frequency of a stretched string related to:

1.  its length?
2. its tension?

Substitution reactions are characteristic reactions of _____ .  (alkynes / alkenes / alkanes)

Action of concentrated sulphuric acid on Sulphur.

Sonia had a recurring deposit account in a bank and deposited ₹600 per month for 2½ years. If the rate of interest was 10% p.a., find the maturity value of this account.

Process of formation of ions from molecules which are not in ionic state.

By drawing an electron dot diagram show the formation of Ammonium Ion [Atomic No.: N = 7 and H = 1]

A battery of e.m.f. 12V and internal resistance 2 Ω is connected with two resistors A and B of resistance 4 Ω and 6 Ω respectively joined in series.

Find:

1. Current in the circuit.
2. The terminal voltage of
...

Penicillin obtained from a fungus is:

1. Antibiotic
2. Antiseptic
3. Antibody
4. Antiserum